# IGCSE Physics: Potetnial Energy and Kineti Energy- Nuemrical Practice Questions

1. Determine the kinetic energy of a 1000-kg roller coaster car that is moving with a speed of 20.0 m/s.
1. If the roller coaster car in the above problem were moving with twice the speed, then what would be its new kinetic energy?
1. Missy Diwater, the former platform diver for the Ringling Brother’s Circus had a kinetic energy of 15,000 J just prior to hitting the bucket of water. If Missy’s mass is 50 kg, then what is her speed?
1. A cart is loaded with a brick and pulled at constant speed along an inclined plane to the height of a seat-top. If the mass of the loaded cart is 3.0 kg and the height of the seat top is 0.45 meters, then what is the potential energy of the loaded cart at the height of the seat-top?
1. A 75-kg refrigerator is located on the 70th floor of a skyscraper (300 meters above the ground) What is the potential energy of the refrigerator?
1. The potential energy of a 40-kg cannon ball is 14000 J.  How high was the cannon ball to have this much potential energy?
1. What is the kinetic energy of a 3-kilogram ball that is rolling at 2 meters per second?
1. The potential energy of an apple is 6.00 joules. The apple is 3.00-meters high. What is the mass of the apple?
1. Two objects were lifted by a machine. One object had a mass of 2 kilograms, and was lifted at a speed of 2 m/sec. The other had a mass of 4 kilograms and was lifted at a rate of 3 m/sec.
Which object had more kinetic energy while it was being lifted?
b. Which object had more potential energy when it was lifted to a distance of 10 meters? Show your
calculation.
2.  You are on roller blades on top of a small hill. Your potential energy is equal to 1,000.0 joules. The last time you checked your mass was 60.0 kilograms. a.What is your weight in newtons?
b. If you start skating down this hill, your potential energy will be converted to kinetic energy. At the
bottom of the hill, your kinetic energy will be equal to your potential energy at the top. What will be
your speed at the bottom of the hill?
3. Answer the following:
What is the kinetic energy of a 1-kilogram ball is thrown into the air with an initial velocity of 30 m/sec?
b. How high into the air did the ball travel? (Hint:KE=PE)
4. What is the potential energy of a 3 kilogram-ball that is on the ground?
5. What is the kinetic energy of a 2,000-kilogram boat moving at 5 m/sec?
6. What is the velocity of a 500-kilogram elevator that has 4,000 joules of energy?
7. What is the mass of an object that creates 33,750 joules of energy by traveling at 30 m/sec?
8. In a lab investigation, one group of students (group A) measures the speed of a 0.1-kilogram car at 2.5 m/sec at the bottom of a hill. Another group of students (group B) measures the speed of the car at 3 m/sec at the bottom of the hill. The car’s starting position at the top of the hill is one-meter high.
What is the potential energy of the car at the beginning of the experiment before its speed is measured?
b. Calculate the kinetic energy of the car for group A using the speed (2.5 m/sec) and mass values above.
c. Calculate the kinetic energy of the car for group B using the speed (3.0 m/sec) and mass values above.