Question

HELP!

1. Calculate the kinetic energy of a car with a mass of 500 kg traveling at a velocity of 10 m/s north.

a. 2,500 J
b. 50,000 J
c. 100 J
d. 25,000 J

2. A rock has a mass of 25 kg. the acceleration due to gravity is 10 m/s^2 and the height of the height of the rock is 42 m. find the potential energy of the rock.

a. 1,050 J
b. 5,250 J
c. 220,500 J
d. 10,500 J

3. Thermal equilibrium is reached when _________.

a. objects have enough kinetic energy for them to be at terminal velocity
b. the sound vibrations reach a high pitch
c. two objects in contract with each other are the same temperature
d. the net force on an object is zero

Answer 1

^^^

1) D

2)D

3)C

Same anwser.

Answer 2

1) Option D

2) Option D

3) Option C

Step-by-step explanation:

1) Kinetic energy
`=(1)/(2) mv^2`

m = 500 kg

v = 10 m/s

Kinetic energy
`=(1)/(2) *500*10^2=25000 J`

Option D is the correct answer.

2) Potential energy = mgh

m = 25 kg

g = 10 m/s²

h = 42 m

Potential energy = 25 * 10 * 42 = 10500 J

Option D is the correct answer.

3) Thermal equilibrium means no heat flow from each other two systems, that is achieved when both systems have same temperature.

Option C is the correct answer.