NEED HELP ASAP!!!
What happens when you push against a brick wall?

A.)The wall pushes back on you with the same force.
B.)The wall noticeably accelerates away from you.
C.)The force of your push is cancelled out by the wall.
D.)The wall pulls you toward it with the same force.

Answer:

a) Andrea's initial momentum, 200 kg m/s

b) Andrea's final momentum, 0

c) Impulse,  = - 200 Ns

d) The force that the seat belt exerts on Andrea, - 400 N

Explanation:

Given data,

The initial velocity of the car is, u = 40 m/s

The mass of Andrea, m = 50 kg

The time period of deceleration, a = 0.5 s

The final velocity of the car, v = 0

a) Andrea's initial momentum,

               p = mu

                  = 50 x 40

                  = 200 kg m/s

b) Andrea's final momentum

                  P = mv

                     = 50 x 0

                    = 0 kg m/s

c) Impulse

                   I = mv - mu

                     = 0 - 200

                    = - 200 Ns

The negative sign indicated that the momentum is decreased.

d) The force that the seat belt exerts on Andrea

                   F = (mv - mu)t

                     = (0 - 200) / 0.5

                     = - 400 Ns

Hence,the force that the seat belt exerts on Andrea is, - 400 N

Answer:

64°

Explanation:

The triangle is an isosceles triangles (both legs are equal to the radius of the circle), so that means the base angles are the same.

Angles of a triangle add up to 180°, so:

128 + 2x = 180

2x = 52

x = 26

∠1 is complementary to the base angle, so:

∠1 = 90 − 26

∠1 = 64

The following can happen to solar radiation when it enters Earth's atmosphere:

Answer: Option A, B, and C

Explanation:

Solar radiation causes an abnormal effect in humans, if they are exposed directly. All the solar radiation emitted by the sun, does not hit us directly. The energy while reaching us passes through different levels of spheres.

Atmosphere contains nitrogen and oxygen molecules, which absorb some of the solar radiation. And some of it is reflected back by the clouds.  And some of the remaining energy is absorbed by the surface of the earth. Likewise, almost 71% of the radiation is absorbed.

Answer: It is absorbed by Earth.

It is reflected by clouds.

It is reflected by glacial ice.

Explanation: Solar radiation is composed of electromagnetic waves that carry energy.

White or shiny surfaces usually reflect some waves (actually almost every surface reflects electromagnetic waves)

So some of the radiation is reflected by clouds or by glacial ice.

The bigest part is actually absorbed by Earth (this is why during the day the temperature increases, a biggest amount of radiation is being absorbed)

Answer:

Yes

Explanation:

This is negative acceleration, also known as deceleration where the speed is reduced from high to low at a specific duration.

Greater the collision

Explanation:

The greater the speed of gas particles in the containers, the greater the collision of gases with the container and between themselves.

Learn more:

Kinetic theory https://brainly.com/question/12362857

#learnwithBrainly

Answer:

cell wall and cell membrane

Answer:

Cell wall and Cell membrane.

Explanation:

The cell membrane controls what goes in and out of the cell

Answer:

The wavelength will be 4 cm, frequency will be 4.66 Hz and wave speed is 18.6 cm/sec

Explanation:

Given:

No. of crest = 13

No. of trough = 15

Time = 3 seconds

Hence, 1 crest or 1 trough = [tex]\frac{1}{2}\lambda[/tex]

therefore,

13 C + 15 T = [tex]28(\frac{1}{2}\lambda)[/tex]

=[tex]14\lambda[/tex]

Time given 3 seconds

  = [tex]\frac{3}{14}s[/tex]

[tex]\nu= \frac{14}{3}[/tex]

[tex]\nu= 4.6 Hz \approx 5 Hz[/tex]

2 cm distance is travelled is time period

[tex]\lambda = 4 cm[/tex]

Again wave will travel in 1 T = 4 cm

wave speed v =[tex]\lambda\times\nu[/tex]

= [tex]4\times\frac{14}{3}[/tex]

= 18.6 cm/s

Using the ground as a reference point the total mechanical energy of  the rock climber is  213,621.15 J.

The total mechanical energy of the rock climber is the sum of its potential energy and kinetic energy. Potential energy is the energy an object has due to its position, while kinetic energy is the energy an object has due to its motion.

To calculate the potential energy, we can use the following formula:

PE = mgh

where:

PE is the potential energy (joules)

m is the mass of the object (kilograms)

g is the acceleration due to gravity (9.81 m/s²)

h is the height of the object above the ground (meters)

To calculate the kinetic energy, we can use the following formula:

KE = 1/2mv^2

where:

KE is the kinetic energy (joules)

m is the mass of the object (kilograms)

v is the velocity of the object (meters per second)

Plugging in the values, we get:

PE = (68 kg)(9.81 m/s²)(320 m) = 213,542.4 J

KE = 1/2(68 kg)(1.5 m/s)² = 78.75 J

Therefore, the total mechanical energy of the rock climber is:

ME = PE + KE = 213,542.4 J + 78.75 J = 213,621.15 J

So the answer is 213,621.15 J

For more such questions on mechanical

https://brainly.com/question/29217523

#SPJ3

Complete question below:

A 68 kg rock climber is 320 meters above the ground and is moving upward at a speed of 1.5 m/s. Using the ground as a reference point, determine the total mechanical energy of the rock climber.

Answer:

-20°C

Explanation:

ΔQ = m c Δt

here ΔQ is heat supplied which is 10 calories , m is mass which is 2 g , c is specific heat capacity of ice which is 0.5 cal/(g C°), Δt is change in temperature which here is to be calculated.

re arranging the equation  we get

Δt = ΔQ/(mc)

   = 10/ ( 2 × 0.5)

 =  10/1

  = 10 C°

final temperature = -30 +10 = -20°C

hence option is A

Answer:

D

Explanation:

Work done w = force F × distance d

F = 200N and d = 5m

: w = 200 × 5

w = 1000J

the ocean creates tides accosiated with the ocean

Answer:

In space, astronauts lose fluid volume—including up to 22% of their blood volume. Because it has less blood to pump, the heart will atrophy.Under the effects of the earth's gravity, blood and other body fluids are pulled towards the lower body.

Explanation:

Chain reactions

Neutrons released in a fission reaction can strike other nuclei and cause chain reactions

Explanation:

In nuclear fission reactions, the heavier atoms split into into lighter atoms, releasing neutrons at high velocity in the process. The neutrons hit other heavier atoms in the vicinity and split them too releasing more neutrons. This continuation is called chain reaction. The more the released neutrons the higher the rate of chain reactions. This causes too much energy to be produced at a go until an enormous explosion occurs (like in bombs).

In controlled nuclear fission such as in nuclear reactors, the number of neutrons is controlled so as to prevent the reactor from exploding. A wall that absorbs excess neutrons is used to control the number of chain reactions to prevent the release of too much energy at once.

Learn More:

For more on chain reactions check out;

https://brainly.com/question/13695900

https://brainly.com/question/1345334

#LearnWithBrainly

Final answer:

Neutrons released in a fission reaction can cause chain reactions, which are sustained cycles of fission that release significant amounts of energy.

Explanation:

Neutrons released in a fission reaction can strike other nuclei and cause chain reactions. This process begins when a neutron collides with a nucleus, such as uranium-235, causing it to split into two smaller isotopes and release additional neutrons. If these neutrons then collide with other uranium-235 atoms, they can cause further fission, perpetuating the cycle. A sustained nuclear chain reaction can lead to the release of large amounts of energy, which is the principle behind both nuclear power generation and the explosive power of nuclear weapons.

Explanation:

total consumption in a month - 1000×2×28= 56000 w-hrs

1 unit = 1Kwh

total unit in month = 56000/1000 = 56

total cost = 56×3 = 168 rs

Answer:

l and lll

Explanation:

Answer:

II only

Explanation:

For heat to flow from one object to another, there must be a temperature difference between them. Temperature is a measure hotness or coldness of an object or a body.

An object consists of vibrating molecules, thus molecular kinetic energy. The measure of the average kinetic energy of an object is its temperature. Thus, when object A has higher temperature (hotter) than B, heat would flow from A to B.

Answer:

Not balanced

Explanation:

The force pulling the object up is applying less force than the object pulling down, this means the object will move down

Answer:

Not balanced

Explanation:

Answer:

White light disperses into full spectrum of color when shined through a prism due to refraction.

Explanation:

This experiment was performed by Isaac Newton when he passed a white light through a glass prism.

Answer:

denisity = 52.33 g/c[tex]m^{3}[/tex]

Explanation:

Density:

[tex]d = \frac{m}{v}[/tex]

We have that m = 785 and that v = 15 c[tex]m^{3}[/tex].

[tex]d = \frac{785}{15}[/tex]

d = 52.33 [tex]m^{3}[/tex]

The density of the object, calculated using the formula Density = Mass/Volume with the given mass of 785g and volume of 15cm³, is found to be 52.33 g/cm³.

The subject in question is about determining the density of an object, which falls under the area of Physics. In physics, density is defined as mass per unit volume, and the formula for calculating density is Density (ρ) = Mass (m)/Volume (V). In the SI system, we often use grams per cubic centimeter (g/cm³) to express the density of solids and liquids.

To apply the formula to this question, we take the mass of the object, which is given as 785g, and then divide this by the volume of the object, given as 15cm³. Thus, the calculation becomes: ρ = 785g / 15 cm³.

The calculated density, to 2 decimal places, is 52.33 g/cm³. Therefore, the object in question has a density of 52.33 g/cm³.

https://brainly.com/question/29775886

#SPJ11

Answer:

2100 J

Explanation:

Draw a picture.  Notice that the rope forms a triangle, where the hypotenuse is L and the height is L cos θ.  The height of the mass is h.  The total height is L, so:

L = h + L cos θ

h = L − L cos θ

The work done by gravity is force times distance:

W = mgh

W = mg (L − L cos θ)

W = (75 kg) (9.8 m/s²) (12 m − 12 m cos 40°)

W = 2063 J

Rounding to two significant figures, the work done is 2100 J.

Answer:Silicon

Explanation:

You add up the protons and neutrons and then look at the element paper

Because specular reflection occurs with a mirror, while diffuse reflection occurs with aluminium or iron plate

Explanation:

Reflection is a phenomenon typical of waves (such as light wave), that occurs when a wave bounces off the surface of a certain material, going back into the original medium at a certain angle, without changing speed, frequency or wavelength.

The direction of the reflected ray is given by the law of reflection, which states that:

Depending on the type of surface, two different types of reflection can occur:

Learn more about reflection and other wave phenomena:

brainly.com/question/3183125

brainly.com/question/12370040

#LearnwithBrainly

It uses water to power large turbines.

Geothermal power taps on the energy of natural steam from the earth's lithosphere.

Explanation:

The heat from deep in the the lithosphere heats up underground water into high-pressure steam trapped in within the rocks. Boreholes are sunk to tap on the potential energy of this high-pressure steam to turn large dynamo turbines that convert the steam energy into electricity.

The biggest advantage, moreover, is the fact that this method of electricity generation does not emit greenhouse emissions as compared to gas plants that burn hydrocarbons that release CO₂.

Learn More:

For more on advantages of geothermal power check out;

https://brainly.com/question/2548426

https://brainly.com/question/4219586

#LearnWithBrainly

Answer:

Ptolemy

Explanation:

Answer:

the name of the 2d Century Roman Scientist and Astrologer who created a set of "Handy  Tables of data to compute the position of the Sun, moon and stars" is:

Explanation:

Ptolemy lived between the year 100 and the year 170 (2nd century), time in which he contributed different bases to astronomy, geography and even astrology. In the first-mentioned area, his geocentric model can be highlighted, with which he mentioned that the Earth It was the center of the universe and therefore it was motionless in the middle of it, and other stars such as the sun or the moon revolved around it and, although in that reasoning it was wrong, it provided fairly accurate means for the time in which the displacement and retrogradation of the planets can be calculated.

Answer:

The height from which the egg is dropped is 68.54 m.

Explanation:

Given:

Initial velocity of egg is, [tex]u=0\ m/s[/tex](Dropped means initial velocity is 0)

Time taken is, [tex]t=3.74\ s[/tex]

Acceleration experienced by egg is due to gravity, [tex]a=g=9.8\ m/s^2[/tex]

The height from which the egg is dropped is, [tex]d=?[/tex]

Now, we use Newton's equation of motion that relates the distance, initial velocity, time and acceleration.

So, we have the following equation of motion:

[tex]d=ut+\frac{1}{2}at^2[/tex]

Plug in all the given values and solve for 'd'. This gives,

[tex]d=0+\frac{1}{2}\times 9.8\times (3.74)^2\\\\d=\frac{1\times 9.8\times 13.9876}{2}\\\\d=\frac{137.078}{2}\\\\d=68.54\ m[/tex]

Therefore, the height from which the egg is dropped is 68.54 m.

Answer:

Temperature increase = 2.1 [C]

Explanation:

We need to identify the initial data of the problem.

v = velocity of the copper sphere = 40 [m/s]

Cp = heat capacity = 387 [J/kg*C]

The most important data given is the fact that when the shock occurs kinetic energy is transformed into thermal energy, therefore it will have to be:

[tex]E_{k}=Q\\ E_{k}= kinetic energy [J]\\Q=thermal energy [J]\\Re-employment values and equalizing equations\\\\\frac{1}{2} *m*v^{2}=m*C_{p}*dT  \\The masses are canceled \\\\dT=\frac{v^{2}}{C_{p} *2} \\dT=2.1 [C][/tex]

The correct option is d. 2.1°C. The increase in temperature of the copper sphere was approximately [tex]\( 2.1 \)[/tex]°C, which corresponds to answer choice D).

Given:

- Initial kinetic energy (KE) of the copper sphere = [tex]\( \frac{1}{2} mv^2 \)[/tex]

- Specific heat capacity of copper, [tex]\( c = 387 \)[/tex] J/(kg·°C)

The entire kinetic energy is converted into thermal energy, [tex]\( Q = mc\Delta T \)[/tex], where [tex]\( \Delta T \)[/tex] is the increase in temperature.

1. Calculate the initial kinetic energy:

[tex]\[ KE = \frac{1}{2} mv^2 \][/tex]

2. Set up the equation equating kinetic energy to thermal energy:

[tex]\[ \frac{1}{2} mv^2 = mc\Delta T \][/tex]

3. Solve for [tex]\( \Delta T \)[/tex]:

[tex]\[ \Delta T = \frac{\frac{1}{2} mv^2}{mc} \][/tex]

4. Substitute the given values:

[tex]\[ \Delta T = \frac{\frac{1}{2} \times m \times (40)^2}{m \times 387} \][/tex]

5. Simplify the expression:

[tex]\[ \Delta T = \frac{800 \times m}{387 \times m} \]\[ \Delta T = \frac{800}{387} \]\[ \Delta T \approx 2.065 \ \textdegree C} \][/tex]

Rounding to one decimal place, the increase in temperature [tex]\( \Delta T \)[/tex] is approximately  [tex]\( 2.1 \)[/tex]°C.

Therefore, the increase in temperature of the copper sphere was approximately [tex]\( 2.1 \)[/tex]°C, which corresponds to answer choice D).

A copper sphere was moving at 40 m/s when it hit another object. This caused all of the KE to be converted into thermal energy for the copper sphere. If the specific heat capacity of copper is 387 J/(kg ⋅ C°), what was the increase in temperature?

a. 0.23 C°

b. 0.81 C°

c. 1.3 C°

d. 2.1 C°

｡☆✼★ ━━━━━━━━━━━━━━  ☾  

Since Pluto is a dwarf planet, the correct option is B. 8

Have A Nice Day ❤    

Stay Brainly! ヅ    

- Ally ✧    

｡☆✼★ ━━━━━━━━━━━━━━  ☾

Answer:

7 m/s

Explanation:

Acceleration, [tex]a=\frac {v-u}{t}[/tex]

Where v and u are the final and initial velocities of the Justine respectively, t is the time taken for Justin to attain final velocity.

Making v the subject then

v=at+u

Taking u as zero then

Substituting 3.5 for t, 2 as a then

v=3.5*2=7 m/s

Answer:

50 J

Explanation:

Work, W=Fd where F is the applied force and d is the distance

Substituting 10 N for F and 5 m for d then work done on the book can be expressed as

W=10 N* 5 m=50 Nm= 50 J

Therefore, the work done is equivalent to 50 J