# Physics

Question: A car is on a ramp 100m from the bottom of the ramp (angle of incline=30 degrees):

a. If the potential energy of the car is 80902 J, how much does the car weigh?

b. What is the KE half way down the ramp?

c. What speed is the car moving at the bottom of the ramp?

Please indicate which equation you use, what variable corresponds to each number, and how you got the number that goes with the variable.

Thanks!

1. 👍 0
2. 👎 0
3. 👁 220
1. a. h = 100sin30 = 50m.

PE = mgh = 80,902J,
m*9.8*50 = 80,902,
m = 165.1kg.

F = mg = 165.1kg * 9.8N/kg = 1618N =
Wt. of car in Newtons.

Wt. = 165.1kg / 0.454kg/lb = 364lbs =
Weight of car in lbs.

b. h = (100/2)sin30 = 25m.
V^2 = Vo^2 + 2gd,
V^2 = 0 + 2*9.8*25 = 490,
V = 22.1m/s.
KE = 0.5mV^2 = 0.5 * 165.1 * (22.1)^2 =
40,318J.

c. V^2 = Vo^2 + 2gd,
V^2 = 0 + 2*9.8*50 = 980,
V = 31.3m/s.

1. 👍 0
2. 👎 0

## Similar Questions

1. ### physics mechanical energy

A skateboarder with mass ms = 42 kg is standing at the top of a ramp which is hy = 3.7 m above the ground. The skateboarder then jumps on his skateboard and descends down the ramp. His speed at the bottom of the ramp is vf = 6.3

asked by carlo on October 7, 2013
2. ### physics

A toy car is given a quick push so that it moves on an inclined ramp. After it is released, it moves up, reaches its highest point and moves back down again. Friction is so small it can be ignored. What net force acts on the car?

asked by alexa on July 2, 2011
3. ### physics

20.) A piano has been pushed to the top of the ramp at the back of a moving van. The workers think it is safe, but as they walk away, it begins to roll down the ramp. If the back of the truck is 1.5 above the ground and the ramp

asked by Anonymous on March 9, 2012
4. ### physics

EXERCISE 4.9 (a) Suppose a hockey puck slides down a frictionless ramp with an acceleration of 5.00 m/s2. What angle does the ramp make with respect to the horizontal? (b) If the ramp has a length of 6.00 m, how long does it take

asked by hisham on November 15, 2012
1. ### Physics

A stunt driver wants to make his car jump over 8 cars parked side by side below a horizontal ramp. A)With what minimum speed must he drive off the horizontal ramp? The vertical height of the ramp is 1.5 m above the cars and the

asked by Somoan on December 6, 2013
2. ### Physics

A 1130 kg -car is being pulled up a frictionless ramp at a constant speed. The cable makes an angle of 31.0 degrees above the surface of the ramp, and the ramp itself rises at 25.0∘ above the horizontal. Find the tension in the

asked by Vick on October 29, 2017
3. ### physics 1401

a 15kg crate initially at rest slides down a ramp 2m long and inclined at an angle of 20 degrees with the horizontal. If there is no friction between the ramp surface and crate, what is the velocity of the crate at the bottom of

asked by jcarrington on June 28, 2015
4. ### physics

A 1.9 kg block slides down a frictionless ramp, as shown in figure 8-28. The top of the ramp is 1.5 m above the ground; the bottom of the ramp is .25 m above the ground. The block leaves the ramp moving horizontally, and lands a

asked by tony on October 20, 2010
1. ### Urgent! Pre-Cal

A wheelchair ramp with a length of 122 inches(top of ramp) and has a horizontal distance of 120 inches(bottom of ramp): a) what is the ramp's vertical distance(x)? b)Construction laws are very specific when it comes to ramps. Each

asked by Dom on June 4, 2016
2. ### physics

I am having great difficulty with this question. A block is placed on a frictionless ramp at a height of 12.5 m above the ground. Starting from rest, the block slides down the ramp. At the bottom of the ramp, the block slides onto

asked by Johnny on October 2, 2014
3. ### physics 2

Question 1: Suppose a child of weight w climbs onto the sled. If the tension force is measured to be 58.5 N, find the weight of the child and the magnitude of the normal force acting on the sled. Question 2 : (a) Suppose a hockey

asked by Michelle J on October 5, 2019
4. ### physics

A car sits in an entrance ramp to a freeway, waiting for a break in the traffic. The driver sees a small gap between a van and an 18-wheel truck and accelerates with constant acceleration along the ramp and onto the freeway. The

asked by Emma on September 29, 2013