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Two kids are roller skating. Amy, with a mass of 55 kg, is traveling forward at 3 m/s. Jenny, who has a mass of 40 kg, is traveling in the opposite direction at 5 m/s. They crash into each other and hold onto each other so that they move as one mass. How fast are they traveling?

Final answer:

The angular velocity is 0.02667 radians/second, the linear velocity is 0.004 m/s, and the periodic time is approximately 235.62 seconds.

This question involves circular motion. We will apply the concepts of circular motion to analyse each part of the question.

a. Angular Velocity

To find the angular velocity (ω), we start by calculating the angle (θ) in radians.

Since 1 complete circle is 2π radians:

θ = s / r = 4 cm / 15 cm = 4 / 15 radians

Given the time (t) is 10 seconds:

ω = θ / t = (4 / 15) / 10 = 4 / 150 radians/second = 0.02667 radians/second

b. Linear Velocity

The linear velocity (v) is related to the angular velocity by:

v = ω r

Here, r = 15 cm = 0.15 m:

v = 0.02667 rad/s × 0.15 m = 0.004 m/s

c. Periodic Time

The periodic time (T) is the time it takes for one complete revolution.

First, we find the circumference (C) of the circle:

C = 2πr = 2π × 0.15 m = 0.3π m

We already know the linear velocity (v):

T = C / v = 0.3π / 0.004 = 75π s ≈ 235.62 seconds

Answer: The electromagnetic waves reach Earth, while the mechanical waves do not.

Explanation:

Answer:

(B) The electromagnetic waves reach Earth, while the mechanical waves do not.

Explanation:

Electromagnetic waves do not require material medium for their propagation, so it will reach the Earth. Mechanical waves require material medium for their propagation, so mechanical waves will not reach Earth.

Therefore, the correct option is B "The electromagnetic waves reach Earth, while the mechanical waves do not".

Answer:

Centripetal acceleration is the acceleration of an object traveling in a circle, while linear acceleration is the acceleration of an object traveling in a straight line.

Answer:

Centripetal acceleration is the acceleration of an object traveling in a circle, while linear acceleration is the acceleration of an object traveling in a straight line. ... Meanwhile linear acceleration is the rate of change of linear velocity, which is the velocity of an object traveling in a straight line.

Answer:

The net force is zero, if there is not external forces. The net force if the body is accelerating will be the product of the mass by the acceleration.

Explanation:

If the box does not accelerate, there are two possible options, either the box moves at constant velocity or does not receive any external force to alter its balance.

Newton's Second Law, also known as the Fundamental Law of dynamics, determines a proportional relationship between Force and variation of the amount of motion or linear moment of a body. In other words, The Force is directly proportional to the mass and acceleration of a body.

[tex]F=m*a\\where:\\m= mass [kg]\\a=acceleration[m/s^2][/tex]

[tex]0=m*a\\a=0[m/s^2][/tex]

If there are forces acting on the body and these forces are not in balance the body will move with a resulting force equal to the product of mass by acceleration.

[tex]F_{net} =m*a[/tex]

Answer:

a) t = 1second

b) KE = 1000Joules

Explanation:

According to equation of motion,

S = ut+1/2at² where

S is the distance or height of fall = 5m

u = initial velocity = 0m/s²

a = +g = acceleration due to gravity = 10m/s²

Substituting the values in the formula to get the time we have,

5 = 0+1/2(10)t²

5 = 5t²

t² = 1

t = 1second

Time taken by the stone to reach the ground is 1second

b) Kinetic energy is the energy possessed by a body by virtue if its motion.

KE = 1/2MV² where m is the mass of the body and v is the velocity.

Given mass = 20kg

To get the velocity, we will use the equation of motion,

v = u + at

v is the final velocity

u is the initial velocity = 0m/s

a = +g = 10m/s

t = time = 1second

v = 0+10(1)

v = 10m/s

KE = 1/2×20×10²

KE = 10×100

KE = 1,000Joules

Answer:

Let's begin by explaining that the electromagnetic spectrum is the set of electromagnetic radiations distributed in their different frequencies or wavelengths. So, if we go from the smallest wavelengths known up to now (because according to physics the electromagnetic spectrum is infinite and continuous) to the longest, the electromagnetic spectrum covers the following radiations:  

Gamma rays, X-rays, ultraviolet, visible light, infrared, radio waves and microwaves:

-Gamma rays: With a wavelength in the order of [tex]10^{-12}m [/tex], is a type of ionizing radiation capable of penetrating matter quite deeply and is able to cause serious damage to the nucleus of the cells.

-X rays: With a wavelength between [tex]1m[/tex] and [tex]10km[/tex]. It is invisible to the human eye, capable of crossing opaque bodies and is also an ionizing radiation.

-Ultraviolet light (UV): Whose wavelength is approximately between 100 nm and 380 nm; is a type of electromagnetic radiation that is not visible to the human eye.  

-Visible light: This part of the spectrum is located between ultraviolet light and infrared light (400 nm - 800 nm). It should be noted, the fact the only part of the whole electromagnetic spectrum is visible to humans is because the receptors in our eyes are only sensitive to these wavelengths.

-Infrared: This type of radiation is not visible to the human eye, since its wavelengths are outside the visible spectrum (between 700 nm and 1 mm).  

These waves can be divided into:  

- Near infrared or long wave infrared: it is the least sensitive to color and is easily absorbed by water.  

- Medium or medium wave infrared: it is also insensitive to color and easily absorbed by water and many types of plastics and paints.  

- Far infrared or short wave infrared: it is more penetrating than the long wave and is good for heating metals, these waves also can pass through clear materials.  

This light has many uses, including heating lamps in physiotherapy and medical treatments, heat sensing devices, among others.

-Radio waves: This is a type of electromagnetic radiation with wavelengths between 10 m to 10,000 m. This type of electromagnetic waves is very well reflected in the ionosphere, the layer of the atmosphere through which they travel directly or using repeaters. In addition, this radiation is important in telecommunications.

Answer:

5 moles of O2are required, you can see it in your equation.

Answer:

5 moles of O2are required, you can see it in your equation.

Explanation:

Answer:

A Anemia

Explanation:

Anemia is a condition in which you lack enough healthy red blood cells to carry adequate oxygen to your body's tissues. Having anemia can make you feel tired and weak. There are many forms of anemia, each with its own cause. Anemia can be temporary or long term, and it can range from mild to severe.

Answer:

18.4 kcal

Explanation:

ΔQ = m c Δ t

where ΔQ is heat energy supplied in kcal , m is mass in kg , c is specific heat capacity which is 0.092 kcal / (kg C°) ,  Δ t = 110-10= 100C°

ΔQ = 2×0.092×100 = 18.4 kcal

Answer:

heat = 20 Kcal

Explanation:

Answer:

(a) [tex]R_5=9\ \Omega[/tex]

(b) Potential Difference = 11.584 V

(c) [tex]R_1=0.40\ \Omega[/tex]

Explanation:

Given:

[tex]\textrm{Current in A₁,}I_1=0.4\ A\\\textrm{Current in A₂,}I_2=0.64\ A\\R_2=5.6\ \Omega\\R_3=6.2\ \Omega\\R_4=8.2\ \Omega\\\textrm{EMF of the battery,}E= 12 V[/tex]

(a)

The resistances [tex]R_3\ and\ R_4[/tex] are in series. So, equivalent resistance is the sum of the two.

[tex]R_s=R_3+R_4=8.2+6.2=14.4\ \Omega[/tex]

Now, [tex]R_s\ and\ R_5[/tex] are in parallel. So, potential difference across both the terminals is same. Therefore,

[tex]I_1R_s=I_2R_5\\\\R_5=\frac{I_1}{I_2}R_s\\\\R_5=\frac{0.4}{0.64}\times 14.4=9\ \Omega[/tex]

(c)

Now, since the resistances are in parallel, the equivalent resistance is given as:

[tex]\frac{1}{R_p}=\frac{1}{R_s}+\frac{1}{R_5}\\\\R_p=\frac{R_s\times R_5}{R_s+R_5}\\\\R_p=\frac{14.4\times 9}{14.4+9}\\\\R_p=\frac{129.6}{23.4}=5.54\ \Omega[/tex]

Now, resistances [tex]R_1,R_2\ and\ R_p[/tex] are in series. Therefore, equivalent resistance is given as:

[tex]R_{eq}=R_1+R_2+R_p\\R_{eq}=R_1+5.6+5.54\\R_{eq}=R_1+11.14-----1[/tex]

Now, from Ohm's law, we know that,

[tex]E=(I_1+I_2)R_{eq}\\\\R_{eq}=\frac{E}{I_1+I_2}\\\\R_{eq}=\frac{12}{0.4+0.64}\\\\R_{eq}=11.54\ \Omega[/tex]

Plug in [tex]R_{eq}[/tex] value in equation (1). This gives,

[tex]11.54=R_1+11.14\\R_1=11.54-11.14=0.40\ \Omega[/tex]

(b)

Now, potential difference across the terminals of the battery is given as:

[tex]V=E-(I_1+I_2)R_1\\V=12-(0.4+0.64)0.4\\V=12-0.416=11.584\ V[/tex]

Answer:

the answer is D.

Explanation:

Acceleration means you can increase in speed, decrease in speed, and change directions. BUT, velocity means speed with a direction. If you want to accelerate, it's impossible to keep the same velocity at the same time.

Answer:

it is potential energy

Explanation:

There is no movement taking place, so it can't be kinetic. There are no chemical reactions, so it isn't chemical energy, and gravity does not take part in the stretching of a rubber band. The stretched spring or rubber band has lots of energy ready to go at any point, but it is not being used at the moment, so it is potential energy.

Answer:

D

Explanation:

wave reflection I think is preferable

Answer: Option B

Explanation: The peak of a wave can be called the "positive" part of the wave, and the trough part of a wave can be called the "negative" part of a wave.

So if these two parts of the wave interfere with each other, they cancel each other (because one is "positive" and the other "negative")

This effect is called Destructive Interference (in the case where two peaks or two troughs interfere, the phenomenon is called constructive interference)

Then the correct option is B

Answer:

Decreases

Explanation:

Ideal gas law:

PV = nRT

where P is absolute pressure,

V is volume,

n is number of moles,

R is gas constant,

and T is absolute temperature.

If V is constant and T decreases, then P must decrease.

In accordance with Boyle's Law, if the volume of a scuba tank remains constant and its temperature decreases, then the pressure of the air within the tank would increase. This principle is applied in underwater activities to ensure safe ascension and descension by divers.

The scenario you're describing falls under the principles of Boyle's law in physics, which applies to scenarios where gases are held at a constant volume. Boyle's law states that the pressure and temperature of a gas have an inverse relationship when held at a constant volume. If we apply this to your question, it implies that if the volume of air in the scuba tank remains constant and its temperature decreases, the pressure within the tank would increase.

For instance, if divers descend into the deep waters, the increase in water pressure compresses the air pocket within the scuba tank, and this increase in pressure subsequently raises the tank's temperature. A reverse scenario will occur during ascent. As divers begin to ascend and water pressure reduces, the air pocket within the scuba tank expands, resulting in a decrease in pressure, subsequently causing the tank's temperature to decrease as well.

The relationship between temperature, volume, and pressure is crucial in subaquatic activities to prevent potential mishaps like ruptured lungs or eardrums due to rapid pressure change.

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Answer:

10.39 OR 10.4 m at 46.6° downward or clockwise with +xaxis or 313.4° in anticlockwise direction with + X-axis

Explanation:

D =  SQUARE ROOT OF(7.14^2 +(-7.55)^2)

 D = 10.39 m

as Dx is positive and Dy IS NEGATIVE hence vector is in 4 th quadrant

tan α= 7.55/7-14

        = 1.057

α = 46.6° downward or clockwise with +xaxis

or  α =313.4° in anticlockwise direction with + X-axis

Answer:

(a) 20.0 Ns

(b) 14.9°

(c) 0.776 m/s

Explanation:

Let's say the astronaut's original velocity is in the x direction.  The impulse from rockets is at a right angle to this, or in the y direction.

(a) Impulse is force times time.

J = (100.0 N) (0.200 s)

J = 20.0 Ns

(b) Impulse is change in momentum.

J = mΔv

20.0 Ns = (100 kg) (vᵧ − 0 m/s)

vᵧ = 0.200 m/s

The angle of the new total velocity, relative to the x direction, is:

θ = atan(vᵧ / vₓ)

θ = atan(0.200 m/s / 0.750 m/s)

θ = 14.9°

(c) The magnitude of the new total velocity is:

v² = vₓ² + vᵧ²

v² = (0.750 m/s)² + (0.200 m/s)²

v = 0.776 m/s

To determine the speed at which the astronaut moves towards the space station after tossing a bag of tools, calculate the initial and final momenta of the system and apply the conservation of momentum principle.

An astronaut is detached from the space station during a spacewalk. To return, she tosses a 12 kg bag of tools away from the station at 5 m/s. Given that her total mass including the suit and equipment is 120 kg, we can calculate the speed at which she will move towards the station.

First, calculate the initial momentum of the system before the tools are tossed. Then, apply the principle of conservation of momentum to find the final velocity of the astronaut. This final velocity will represent the speed at which she moves towards the space station.

The process involves setting the initial momentum (before the toss) equal to the final momentum (after the toss) and solving for the final velocity.

The cruise liner’s speed when it collided with the iceberg if it had a mass of 4.23 x 108 kg ship and a momentum of 4.9 x 109 kg·m/s is v= 11.584 m/s

Explanation:

Given :

The cruise liner’s speed when it collided with the iceberg has a

Mass (m) = 4.23 x 108 kg  and

Momentum (p) = 4.9 x 109 kg m/s

To calculate the momentum,

We need to use the formula of a momentum

Momentum = Mass x Velocity ( p = m v )

as we need to find the velocity the formula becomes

velocity = momentum / mass

v = p / m

= (4.9 x 109 kg m/s) / (4.23 x 108 kg)

v= 11.584 m/s

Answer:

(1) Initial speed, [tex]u=0[/tex]

    Final speed, [tex]v=165.76m/s[/tex]

    Average speed, [tex]v_a_v_g=82.87m/s[/tex]

(2) Force of gravity, [tex]F_g=12.8\times10^1^5N[/tex]

Explanation:

(1)

Given,

Distance, [tex]S=300meter[/tex]

Time, [tex]t=3.62second[/tex]

It is given that drag racer started at rest.

So Initial speed, [tex]u=0[/tex]

Using Newton's second equation of motion,

[tex]S=ut+\frac{1}{2}at^2\\300=0+\frac{a\times3.62^2}{2} \\a=45.79m/s^2[/tex]

Newton's first equation of motion,

[tex]v=u+at\\=0+45.79\times3.62\\=165.76 m/s[/tex]

So, Final speed, [tex]v=165.76m/s[/tex]

Average speed is defined as totle distance divided by totle time.

[tex]v_a_v_g=\frac{S}{t}\\=\frac{300}{3.62} \\=82.87m/s[/tex]

So, Average speed, [tex]v_a_v_g=82.87m/s[/tex]

(2)

Gravitation: It is the natural phenomenon in which two different bodies attract each other by virtue of their masses.

       According to Newton's law of gravitation, the force of attraction between two bodies is directly proportional to the masses of the bodies and inversely proportional to square of distance between centers of mass of the bodies.

                         [tex]F_g\propto\frac{m_1m_2}{r^2} \\F_g=G\frac{m_1m_2}{r^2}[/tex]where [tex]G[/tex]is constant of proportionality and known as gravitation constant.

Given,

Mass of Jupiter, [tex]m_1=1.9\times10^2^7kg[/tex]

Mass of Ganymede, [tex]m_2=1.48\times10^2^3kg[/tex]

Distance between their centers of mass, [tex]r=1.21\times10^1^2meter[/tex]

[tex]F_g=G\frac{m_1m_2}{r^2}\\=\frac{6.67\times10^-^1^1\times1.9\times10^2^7\times1.48\times10^2^3}{(1.21\times10^1^2)^2} \\=12.8\times10^1^5N[/tex]

So, Force of gravity, [tex]F_g=12.8\times10^1^5N[/tex]

Answer:

physical quantity that only has magnitude and no other characteristics.

Explanation:

so no velocity only magnitude

Answer:

Time and speed is a pair of scalar quantities.

Explanation:

this questions answer choices  are  imcomplete  it should be like this .

Which of the following is a pair of scalar quantities?

A.) velocity - distance

B.) velocity - displacement

C.) time - speed

D.) time - displacement

Answer:

Net force is Zero.

Explanation:

If all forces that are equal and opposite are exerted on an object the resulting force will be Zero.

Answer:

If the net force in the stuffed toy is zero, this means that the forces that the children apply on the toy cancel each other.

This can happen if, for example, two kids pull by one side with a force F and the other two kids pull by the other side with the same force -F (the minus sign is because the direction is the opposite)

Then, the total force is F + (-F) = F - F = 0

Final answer:

The loudness of a sound is primarily determined by the amplitude of the sound wave, where larger amplitudes result in louder sounds. This is measured in decibels (dB). The perceived loudness also depends on the force of vibration and the frequency sensitivity of the human ear.

Explanation:

The loudness of sound is determined by the amplitude of vibration. The amplitude, or height of the sound wave, dictates how much energy it carries, subsequently influencing its perceived loudness or volume.

A wave with a larger amplitude carries more energy, resulting in a louder sound, while a smaller amplitude corresponds to a softer sound. This is why sound C in a diagram with higher amplitude waves is louder than sound B with lower amplitude waves.

Loudness is often measured in decibels (dB), with larger waves and consequently greater amplitudes reflected in higher decibel levels. As an example, a typical conversation may measure around 60 decibels, considerably louder than a faint whisper at 30 decibels, illustrating the impact of amplitude on the loudness of sounds we encounter daily.

However, the strength of the sensation, or intensity, also plays a role, mainly governed by the force behind the vibrating body - more force results in a wider vibration and greater intensity.

Yet, the ear's sensitivity to different frequencies also affects perceived loudness; we may perceive sounds as louder if they are within the frequency range where the ear is most sensitive.

Answer:

Normal force of 10,000N

Explanation:

From the question, the weight the car exerts on the pavement is 10,000N.

The pavement exerts upward and perpendicular contact force called normal force on the car to support its weight. Also, the normal force is equal and opposite to the weigh of the car.

Hence the pavement exerts normal force of 10,000N back on the car to prevent it from passing through it.

Final answer:

The pavement exerts an equal and opposite force of 10,000 newtons back on the car due to Newton's third law of motion. The net force and net torque on a stationary car parked on level pavement are zero.

Explanation:

If a car parked on level pavement exerts a force of 10,000 newtons (N) on the ground, the pavement exerts an equal and opposite force of 10,000 N back on the car. This is due to Newton's third law of motion, which states that for every action, there is an equal and opposite reaction.

In this case, the action is the force of the car's weight on the pavement, and the reaction is the normal force exerted by the pavement on the car. The force exerted by the pavement is also known as the support force and it is what prevents the car from sinking into the ground.

The net force on the car when it is parked and at rest on level pavement is zero because the downward gravitational force (weight of the car) is balanced by the upward normal force from the pavement. Similarly, the net torque on the car is also zero, assuming no other external forces are acting on it, such as wind or a slope that could create a rotational effect.

Answer:

The term thermodynamics comes from the Greek words therme (heat)  and dynamis (force)

Explanation:

Thermodynamics can be defined as the science of energy. Thought everything  the world has an idea of what energy is, it's hard to define it precisely.

Energy can be considered as the ability to cause change.

The term thermodynamics comes from the Greek words therme (heat)  and dynamis (force), which corresponds to the most descriptive of the first  efforts to convert heat into energy. At present, the concept is  interpret broadly to include Energy Aspects and their transformations,  including power generation, cooling and relationships  among the properties of matter.

The study of thermodynamics examines how heat, work, temperature, and energy are related. The general topic of thermodynamics is the transfer of energy from one location or form to another.

The fundamental idea is that heat is a type of energy that is equivalent to a specific quantity of mechanical labor.

Although the necessity to improve the performance of steam engines prompted the fast development of thermodynamics throughout the 19th century, the principles of thermodynamics are so broadly generic that they apply to all physical and biological systems.

The rules of thermodynamics, in particular, provide a thorough explanation of all changes in a system's energy state and its capacity to do beneficial work on its surroundings.

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Gravitational potential energy is converted into kinetic energy

Explanation:

There are two forms of energy involved in the situation described in the problem:

In this problem, Sonja and the bike starts from the top of the hill and they ride downhill. As they go downhill, their altitude from the ground (h) decreases, so their gravitational potential energy decreases; at the same time, since the total energy is conserved (in absence of friction or air resistance), the speed of the bike and Sonja increases, and their kinetic energy increases. Therefore, there is a conversion of energy from gravitational potential to kinetic.

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Answer:

1 percent

Explanation:

It says that only 3 percent of the water is fresh. So it can be 1 percent or 3 percent. But then it says that most of the water is locked up in glaciers and polar ice caps. So the animals would have a hard time getting to this water. So the rest is available for them. Approximately 1 percent is most reasonable.

Answer:

1 percent (A)

The internal energy produced during this process is 450 J.

Answer: Option C

Explanation:

We know, that work done to perform a displacement will be equal to the change in the kinetic energy as per work energy theorem. Also the work done on that object can be determined by the product of force with displacement.

As the force here is applied in horizontal direction with magnitude of 25N. And with this force, the box got displaced by 30 m.  So,

       [tex]\text { Workdone }=\text { Force } \times \text { Displacement }=25 \times 30=750 \mathrm{J}[/tex]

But, according to work energy theorem, the workdone should be equaled to the variation in kinetic energy. While here, the kinetic energy has been found to change as 300 J in positive side.

So, the variation in kinetic energy is not matching with the work done to displace the box. Hence, it can be concluded that the difference in work done and modified kinetic energy will be giving the total internal energy of the box. Thus,

       [tex]Total internal energy of the box = Work done - Kinetic energy =750-300=450 \mathrm{J}[/tex]

The equivalent resistance of the parallel circuit with three resistors is determined as 1.64 ohms.

The equivalent resistance of the parallel circuit is determined as follows;

¹/R = ¹/R₁ + ¹/R₂ + ¹/R³

¹/R = ¹/3 + ¹/6 + ¹/9

¹/R =   (6 + 3 + 2)/18

¹/R = 11/18

R = 18/11

R = 1.64 ohms

Thus, the equivalent resistance of the parallel circuit with three resistors is determined as 1.64 ohms.

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Final answer:

The equivalent resistance of the circuit with three resistors in parallel (3.0 Ohms, 6.0 Ohms, 9.0 Ohms) is approximately 1.636 Ohms.

Explanation:

To find the equivalent resistance of a circuit consisting of resistors in parallel, one must use the formula for parallel resistors, which is 1

In this case, the circuit has three resistors in parallel with resistances of 3.0 Ohms, 6.0 Ohms, and 9.0 Ohms. Hence, the calculation for the equivalent resistance (R_eq) is:

1/R_eq = 1/3.0 Ohms + 1/6.0 Ohms + 1/9.0 Ohms

1/R_eq = 1/3 + 1/6 + 1/9

1/R_eq = 6/18 + 3/18 + 2/18

1/R_eq = 11/18

Now, take the reciprocal to find the equivalent resistance:

R_eq = 18/11 Ohms

R_eq ≈ 1.636 Ohms

Therefore, the equivalent resistance of the three parallel resistors is approximately 1.636 Ohms.

Answer:

its true on practice test ed

Explanation:

Culture creates the context for behavior in society. Culture plays a major role in the lives of everyone living in the society.  The given statement is true.

Culture is such a powerful influence on the outlooks and behaviors which often we are not even aware of it, instead of believing the perspectives are just the way things are. In the context of increasingly diverse classroom settings, such as the unexamined beliefs can lead to avoidable conflict and a loss of valuable things.

A culture creates the context for behavior through the reinforcements and punishments which it provides for each discrete behavior. By shaping the behaviors, cultures that reaffirm acceptable behavior and discourage deviant behavior.

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Answer:

2 protons, 2 electrons and 1 neutron

Explanation:

Answer:

B. 68.6m

Explanation:

Free Fall Motion

When a body is left to move in the air with no friction, the motion is ruled only by the force of gravity. The vertical distance a body travels in the air after a time t is .

[tex]\displaystyle y=\frac{gt^2}{2}[/tex]

We know the egg takes 3.74 seconds to reach the ground. The height it was launched from is

[tex]\displaystyle y=\frac{(9.8)(3.474)^2}{2}[/tex]

[tex]\displaystyle y=68.54\ m[/tex]

The closest correct option is

B. 68.6m