Name _________________
Date ______ Period _____
Alternative Assignment
Directions: Use your notes to complete the word problems below. You must show ALL work to get
full credit!!!
1. An aluminum block has a density of 2.70 g/mL. If it has a volume of 15 mL, what is its mass?
2. You have built an engine for your science fair project and want to test it's efficiency. You put in enough gas
to produce 150 J of work (input). Your engine produces 134 J of mechanical energy output. What is your
engine's efficiency?
3. You use a carjack (lever) to prop up your car to change the tire. With your foot, you apply 4 N of Force. The
weight of the car being lifted is 2500 N. What is the mechanical advantage of the carjack?
4. You pull down on a pulley rope with a force of 15 N. If the mechanical advantage of the pulley is 13, how
many birthday cakes (each with a weight of 19.5 N) can you lift using this pulley?
5. A toy boat with a mass of 1350 g was pushed with a force of 55 N. What was its acceleration?
6. A lightbulb has a power of 60 Watts. In 5 seconds, how much work is done by the lightbulb?
7. A bulldozer performs 75,000 J of work pushing dirt 18 m. What was the force exerted?
8. What would your weight on Jupiter be if your mass is 52 kg? The acceleration due to Jupiter's gravity is 24.5
m/s/s
9. A farmer's tractor broke down on a muddy hill. In order to tow it back to the barn, he had to try and pull it out
of the mud. Even though the farmer pulled with a force of 600 N, the tractor still slid backwards down the hill
4.5 meters. How much work was done by the farmer?
10. A machine produces 4000 J of work in 5 seconds. How much power does the machine produce?