Chapter 4 & 5 Review Worksheet

1) An 80.0 kg person carries 25 N package up a flight of stairs. The vertical height of the stairs is 10.0 m. How much work is done?

2) A force of 1800 N is needed to keep a piano from sliding down a 10.0 m ramp. How much work is done?

3) A child pulls a sled through the snow with a force of 45 N applied to rope at an angle of 30.0° with the horizontal. How much work is done it they moved 15 m?

4) It takes 7500 J of work to slide a crate a distance of 15 m across a floor. A force of 650 N was applied to the rope. What angle did the rope make with the ground?

5) It took a force of 250 N to pull a crate weighing 765 N across the floor. The work done was 3500 J. How far was the crate moved?

6) A student with a mass of 80.0 kg runs up three flights of stairs in 12 s. The student has gone a vertical distance of 8.0 m. What is the student’s power?

7) A 9.0 kW motor lifts a 3200 kg elevator to a height of 9.5 m. How long does it take?

8) A force of 300 N is used to push a 145 kg mass 30 m in 3 s. Calculate the power.

9) If a rocket is launched with a velocity of 8.0 x 10³ m/s, how high does it rise?

10) A 1500 kg car traveling at 30.0 m/s has the same kinetic energy as a 4500 kg truck. What is the speed of the truck?

11) A 2.0 x 10³ kg car is pulled 345 m up a hill that make s an angle of 15° with the horizontal. What is the potential energy of the car at the top of the hill? If the car rolls down the hill, what will its speed be if we neglect friction?

12) A 75 kg person, starting from rest, slides down a slide 4.0 long inclined at an angle of 35° with the ground. The person reaches the bottom at a speed of 6.0 m/s. What percent of the potential energy was converted to heat?

13) A 4.0 kg ball starts from rest and rolls down a hill 3.5 m high and up an adjoining hill 2.5 m high. What will its speed be when it reaches the top of the second hill?

14) A 14700 N car is traveling at 25 m/s. The brakes are suddenly applied and the car slides to a stop. The average braking force between the tires and the road is 7100 N. How far will the car slide once the brakes are applied?

15) The regulation height for women’s’ high hurdles for high school competition is 84 cm. With what speed must a female hurdler leave the ground in order to clear the hurdle at a speed of 1.0 m/s?

16) A boulder weighing 2.0 x 10⁴ N is resting on a hillside with a slope of 37° . What force tends to cause the boulder to slide down the hill?

17) A store owner wishes to hang a sign weighing 750 N so that cable A attached to the store makes a 30.0° angle as shown below. Cable B is attached to an adjoining building. Calculate the necessary tension in cable B.

18) A box weighing 215 N placed on an inclined plane that makes a 45.0° angle with the horizontal. Compute the component of the gravitational force acting down the inclined plane.

19) A 4.0 kg rock is thrown from the top of a hill 60.0 m above sea level using a catapult. The rock leaves the catapult with a speed of 20.0 m/s. As shown in the diagram below, the rock lands at the bottom of a ravine 40.0 m below sea level. Calculate the speed of the rock just before it hits the bottom of the ravine.