Work
Potential Energy
Kinetic Energy
Conservation
RollerCoaster
100
A car begins moving with a kinetic energy equal to 9 J. The car reaches the top of a mountain and stops. The gravitational potential energy of the car is 8 J at this point. Calculate the total amount of work done by the ramp on the car.
9-8 = 1 J
100
A 40kg ball is pushed up a 900m tall ramp. Determine the amount of potential energy the ball has when it reaches the top.
40*10*900 = 360,000 J
100
A car is moving along a frictionless road with a velocity of 20m/s. The car has a mass of 2kg. Determine the kinetic energy of the car.
1/2 (2) 20^2 = 400 J
100
Mr. Johnson is throwing a basketball. The 2kg basketball leaves his hand with a velocity of 30m/s. Determine the potential energy of the ball when it reaches its highest point.
1/2 (2) 30^2 = 900 J
100
A rollercoaster goes down a ramp. When does the rollercoaster have a maximum amount of kinetic energy?
When it reaches the lowest point of the ramp.
200
A box is pushed up 3 different length ramps of lengths L1, L2, and L3 where L1<L2<L3. The vertical height of all the ramps is equal to h. If the person pushing the box applies a force of F in all 3 scenarios, determine which ramp requires the most work.
All the same because same Force and displacement.
200
A 10kg person with a 2kg backpack stands on a 2m tall hill. A 20kg dog with a 1kg vest stands on a 1m tall hill. Does the person or dog have more potential energy?
12*10*2=240 J
21*10*1=210 J
The person has more.
200
A ball rolls down a frictionless ramp. A scientist tells you the total energy at the top of the ramp is 399 J. What is the kinetic energy at the bottom of the ramp when it is at a height of 0m?
399 J
200
The kinetic energy of a speeding car is 800 J. The car drives up a hill and comes to a stop. It has a potential energy at the top of the hill of 790 J. Was the total energy conserved?
No
200
When does a rollercoaster have the maximum amount of potential energy?
When it reaches the highest height.
300
A 50N dog climbs a mountain that is 20m tall in 5 seconds. How much work does the dog do?
50*20= 1000 J
300
When does a rollercoaster have the most amount of potential energy if it is dropped from rest and has no energy enter or leave the system?
At its highest point
300
Draw the motion map for a car that has a constant kinetic energy as it travels along a frictionless surface to the left.
Equal length arrows pointing left.
300
A 6 kg block is thrown up a vertical ramp with a velocity of 3m/s. The block reaches its highest point at 20m. Was the total energy conserved?
1/2 (6) 3^2 = 27m
No
300
A rollercoaster goes down a ramp. The next hill is half the height of original hill. How much potential energy does it have compared to the original hill?
Half the PE
400
A 100kg ball is thrown down a distance of 200m. How much energy does the ball hit the earth with if the total energy is conserved?
100*10*200 = 200,000 J
400
A car is dropped from rest from a very tall crane. Assume the force of air is negligible. The kinetic energy at the instant the car hits the ground is 200 J. Determine the amount of potential energy the car has before it is dropped.
200 J
400
A person is skydiving out of a plane at 39,000 feet. The person reaches a terminal velocity of 130m/s as they are falling to the earth. The person has a mass of 40kg. What is the kinetic of the energy of the person?
1/2 (40) 130^2 = 338,000 J
400
Bill drops a 1kg balloon from a height of 30m. Determine the final velocity of the balloon right before it hits the ground.
1(10)(30) = 300 J = 1/2(1)v^2
v=24.5m/s
400
Joey is going upside down on a rollercoaster that is 1/4 the height of the original hill he started on. How much PE does he have at this point?
1/4 PE
500
The power rating of a car is rated at 20000 watts for every 30 seconds the car is running. Determine the amount of energy the car uses up during this time.
20000*30 = 600,000 J
500
A 900kg marker is thrown vertically into the air. The maximum height it reaches is 20m. Determine the potential energy of the marker when it reaches the highest point.
900*10*20 = 180,000 J
500
A ball is pushed up an inclined plane by using a force sensor. The potential energy vs distance graph is shown below. Sketch the kinetic energy graph assuming total mechanical energy remains constant.
negative linear line
500
A ball rolls down an inclined plane. The ball hits a block that stops it halfway down the ramp. The ball is 8kg. The ball begins with 200J of energy. How much potential energy does the ball have halfway down the ramp?
100 J
500
A car is released from rest at the top of the hill. Determine the amount of kinetic energy it has when it is halfway down the hill.
Half the potential energy it started with.