# Kinetic energy

#### theevilfly1234

Hello, I know this might seem easy to most people but I’m personally struggling in my physics class. My question states: A 0.05 kg car starts from rest at a height of 0.95m. Assuming no friction, what is the kinetic energy of the hill?(Assume g=9.81 m/s^2)
A.0.466 joules
B. 0.308 J
C. 4317 J
D. 0.0475 J
Also requires me to show work or a way of solving it. I’m lost on what equation to utilize to solve it or better yet how to solve it in general.

Last edited:

#### Cervesa

Hello, I know this might seem easy to most people but I’m personally struggling in my physics class. My question states: A 0.05 kg car starts from rest at a height of 0.95m. Assuming no friction, what is the kinetic energy of the hill?(Assume g=9.81 m/s^2)
A.0.466 joules
B. 0.308 J
C. 4317 J
D. 0.0475 J
Also requires me to show work or a way of solving it
how does a hill have kinetic energy? maybe you should re-check the question statement again.

topsquark

#### topsquark

Forum Staff
Hello, I know this might seem easy to most people but I’m personally struggling in my physics class. My question states: A 0.05 kg car starts from rest at a height of 0.95m. Assuming no friction, what is the kinetic energy of the hill?(Assume g=9.81 m/s^2)
A.0.466 joules
B. 0.308 J
C. 4317 J
D. 0.0475 J
Also requires me to show work or a way of solving it. I’m lost on what equation to utilize to solve it or better yet how to solve it in general.
Given the answer key I suspect you are looking for the gravitational potential energy of the car at the top of the hill?

-Dan

#### theevilfly1234

how does a hill have kinetic energy? maybe you should re-check the question statement again.
It won’t let me edit the comment but I meant to say “what is the kinetic energy of the car when it reaches the bottom of the hill”

#### theevilfly1234

Given the answer key I suspect you are looking for the gravitational potential energy of the car at the top of the hill?

-Dan
No it states what is the kinetic energy of the car when it reaches the bottom of the hill

#### Cervesa

conservation of energy

gravitational potential energy at the top of the hill = kinetic energy at the bottom of the hill

topsquark

#### theevilfly1234

conservation of energy

gravitational potential energy at the top of the hill = kinetic energy at the bottom of the hill
Ok but since I’m looking for kinetic energy, how would I solve this without an indication of the velocity.

#### Cervesa

what is the formula for gravitational potential energy?

#### theevilfly1234

what is the formula for gravitational potential energy?
Had to search this up ngl, but mass multiplied by G^2 multiplied by height. I went ahead and did the equation myself and got 4.57 which isn’t one of the options so I don’t know what I did wrong.

#### theevilfly1234

what is the formula for gravitational potential energy?
I also looked into it further and simply did Mass multiplied by height and got 0.0475J which is D on the answer sheet. Would that be correct?