For this problem, use the following assumptions:

• The lift hill of your roller coaster is 40m tall
• The mass of the roller coaster car is 100kg
• The car's velocity is 0 m/s at the very top of the lift hill
• The bottom of the lift hill is 0m above the ground 

1. What is the downward force due to gravity experienced by the car? (Answer)
2. What is the work done by the engine to pull the car up the lift hill? (Answer)
3. What is the potential energy of the car at the top of the hill? (Answer)
4. What was your change in potential energy as the engine pulled the car to the top of the hill? (Answer)
5. If it took 30 seconds for the engine to pull the car to the top of the lift hill, how much power had to be provided by the engine? (Answer)
6. If the second hill is 10m tall, how fast will the car be moving as it travels over it? (Answer)
7. If you replaced the engine with an 800W engine, how long will it take the car to travel up the lift hill? (Answer)
8. If you replaced the engine with a 400W engine, but lightened the car to 50kg, how long will it take the car to travel up the lift hill? (Answer)