# Will the car make it to the top of the hill?

## Homework Statement

A 1500 kg car is approaching an icy (i.e. frictionless) hill as shown below. The car then runs out of gas traveling at a speed of 10 m/s. a) Will the car make it to the top of the hill?

picture is attached

## Homework Equations

vf^2 = vi^2 + 2ax[/B]

## The Attempt at a Solution

Vf is 0. Vi is 10. x is 10 (sin30 = 5/x)

0 = 0 +10a

i'm lost here at acceleration. If the car is running out of gas, how are we supposed to know how much it is slowing down by? :(

#### Attachments

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billy_joule
What force causes the car to slow down?

Are you familiar with kinetic energy? and gravitational potential energy?

What force causes the car to slow down?

Are you familiar with kinetic energy? and gravitational potential energy?

1/2mvi^2 + mgh = 1/2mvf^2 + mgh

75000+73500=750vf^2+147000

vf = 1.4

as for what forces cause the car to slow down...i would say friction but this problem says frictionless.

billy_joule
You've found the correct speed.
You're right that there is no frictional force. What other forces are acting on the car? Can you draw a free body diagram? The relevant force is the same force that's stopping you from floating up out of your chair right now..

You've found the correct speed.
You're right that there is no frictional force. What other forces are acting on the car? Can you draw a free body diagram? The relevant force is the same force that's stopping you from floating up out of your chair right now..

Gravitational force. The gravitational force will point straight down which will be (9.8 x 1500) = 14700 N.

billy_joule