PHYSICS
MIDDLE SCHOOL

Answer: The anwser is newtons 1st law

HIGH SCHOOL

PLEASE HELP WILL GIVE BRAINLIEST!!!!!!!!!!!!!1 The velocity of a car reduces from 30 km/h to 5 km/h as the car approaches a stop sign. Is this an example of positive or negative acceleration? (circle the correct answer)

A negative acceleration.

negative acceleration

HIGH SCHOOL

Which of the following would not increase the velocity of a sound wave in air? A. increasing the temperature of the air.

B. lowering the density of the air.

C. lowering the humidity of the air.

D. increasing the wind speed in the direction the wave is traveling

D. increasing the wind speed in the direction the wave is traveling

C lowering the humidity of the air

COLLEGE

Solar cells convert the energy of incoming light to electric energy; a good quality cell operates at an efficiency of 15%. Each person in the United States uses energy (for lighting, heating, transportation, etc.) at an average rate of 11 kW. Although sunlight varies with season and time of day, solar energy falls on the United States at an average intensity of 200 W/m². Assuming you live in an average location, what total solar-cell area would you need to provide all of your energy needs with energy from the sun?

Answer:

A = 367 m^2 , The required coverage area of the solar panels

Explanation:

Given:

- The average rate of energy used in USA P = 11 KW

- Solar cells operate with an efficiency e = 15 %

- Solar energy has the irradiation flux of G = 200 W/m^2

Find:

what total solar-cell area would you need to provide all of your energy needs with energy from the sun?

Solution:

- The total amount of flux converted into useful energy by solar cells and delivered to transmission lines in USA is as follows:

P = e*G*A

Where, A is the coverage area of the solar cells.

- Since, it is required for the solar panels to produce P = 11 KW to meet all of USA energy requirements:

11*10^3 = 0.15*200*A

A = 11*10^3 / 0.15*200

A = 367 m^2

COLLEGE

The transfer of excess charge through a conductor to earth is called?

I think it is Grounding.

MIDDLE SCHOOL

Which air masses would have cold, moist air? A.

continental tropical

B.

maritime polar

C.

maritime tropical

D.

continental polar

C) Martime tropical air mass would have cold, moist air.

COLLEGE

What variables must be held constant for avogadro's law to be true?

Pressure and temperature must be held constant for Avogadro's law to be true.

What do you mean by Avogadro's law?Avogadro's law may be defined as a law that states that equal volumes of different gases contain an equal number of molecules under the situation of constant temperature and pressure.

According to Avogadro's law, the volume and amount of gas are directly proportional if the temperature and pressure of the surrounding environment remain constant.

Therefore, it is well described above.

To learn more about Avogadro's law, refer to the link:

brainly.com/question/2761055

#SPJ2

Pressure and temperature.

COLLEGE

student drove to the university from her home and noted that the odometer on her car increased by 14.0 km. The trip took 18.0 min. (a) What was her average speed? (b) If the straight-line distance from her home to the university is 10.3 km in a direction 25.0° south of east, what was magnitude of her average velocity?

Answer:

a) Her average speed was 0.778 km/min

b) Her average velocity was 0.572 km/min

Explanation:

a) The average speed is given by the traveled distance over time:

average speed = distance / time

average speed = 14.0 km / 18.0 min = 0.778 km/min

b) The average velocity is given by the displacement over time. It is calculated as the variation of the position over time relative to the frame of reference. In this case, the origin of the frame of reference is located at the home of the student. The final position will be the university. Then:

velocity = (final position - initial position)/ time

velocity = 10.3 km / 18.0 min = 0.572 km/min

COLLEGE

A .5 kg air puck moves to the right at 3 m/s, colliding with a 1.5kg air puck that is moving to the left at 1.5 m/s. 1. Determine the direction and speed of the pucks' motion if they stick to each other after the collision.

2. Suppose instead that the pucks do not stick together. If the 1.5kg puck moves to the right at .231 m/s after the collision, was the collision elastic? Provide evidence!

3. Determine the size and direction of the average force acting on the .5kg puck during the second collision, if the collision lasted for 25 ms.

Answer:

Explanation:

Total momentum of the system before the collision

.5 x 3 - 1.5 x 1.5 = -0.75 kg m/s towards the left

If v be the velocity of the stuck pucks

momentum after the collision = 2 v

Applying conservation of momentum

2 v = - .75

v = - .375 m /s

Let after the collision v be the velocity of .5 kg puck

total momentum after the collision

.5 v + 1.5 x .231 = .5v +.3465

Applying conservation of momentum law

.5 v +.3465 = - .75

v = - 2.193 m/s

2 ) To verify whether the collision is elastic or not , we verify whether the kinetic energy is conserved or not.

Kinetic energy before the collision

= 2.25 + 1.6875

=3.9375 J

kinetic energy after the collision

= .04 + 1.2 =1.24 J

So kinetic energy is not conserved . Hence collision is not elastic.

3 ) Change in the momentum of .5 kg

1.5 - (-1.0965 )

= 2.5965

Average force applied = change in momentum / time

= 2.5965 / 25 x 10⁻³

= 103.86 N

COLLEGE

An electron is brought from rest infinitely far away to rest at point P located at a distance of 0.033 m from a fixed charge q. That process required 111 eV of energy from an eternal agent to perform the necessary work.

Answer:

The potential at point P is -111 Volt.

Explanation:

Given that,

Distance = 0.033 m

Work = 111 ev

Suppose what is the potential at point P?

We need to calculate the potential at point P

Using formula of potential

Where, W = work

q = charge

Put the value into the formula

Hence, The potential at point P is -111 Volt.