Physics 11 Worksheet – Chapter 6 Solve the following problems. Place your answers on a separate sheet of paper. 1. A student uses a force of 10.0 N to push her physics textbook a distance of 0.50 m across a table. Calculate the amount of work she does on the book. 2. A wrestler lifts his opponent of mass 110 kg to a height of 2.8 m above the floor of the wrestling ring. How much work did the wrestler do on his opponent? 3. A child pulls his wagon a distance of 15 m across the garden while applying a force of 160 N on the wagon’s handle. If the handle makes an angle of 40o with the horizontal, how much work did the child do on the wagon? 4. What is the kinetic energy of a 1000 kg car travelling at 25 m/s? 5. A man does 50 J of work to push a 3.0 kg shopping cart out of her way. If the cart started from rest, what was its speed immediately after this push? (Assume there is no friction.) 6. A 65 kg diver is standing on a diving platform 10.0 m above the water below. What is the gravitational potential energy of the diver with respect to the water’s surface? 7. If the diver in question 6 falls from the diving platform, what is her speed just as she strikes the water? 8. When a block of mass 2.2 kg is 80.0 cm above the end of a spring, it is moving downward at 4.00 m/s. If the spring constant is 65 N/m, what is the maximum compression of the spring? Measure all distances from the point where the block first touches the uncompressed spring. Neglect the mass of the spring. 9. A diver (mass = 75.0 kg) walks to the end of a flexible diving board. The end of the board bends down a distance of 0.55 m, as shown in the diagram on the next page. The diver’s weight on the diving board makes it behave like a spring. (a) Determine the spring constant of the diving board. (b) Calculate the diver’s maximum speed as the board springs back to its equilibrium position. (c) What is the diver’s maximum height above the board’s equilibrium position? 10. Two students, Maya and Luis, are doing work lifting heavy books. Maya can do twice as much work as Luis in twice as much time. How do their power ratings compare? (a) they are equal (b) Maya has the larger power rating (c) Luis has the larger power rating(d) more information is needed to determine which student has the larger power rating 11. A 2.0 kg ball is placed against a spring of force constant 750 N/m, which has been compressed 0.28 m, as illustrated in the diagram above. The spring is released and the ball moves along a horizontal frictionless surface and up a ramp. Calculate the (a) maximum elastic potential energy of the spring (b) maximum velocity of the ball (c) maximum vertical height of the ball on the ramp 12. An elevator motor lifts the elevator full of passengers a height of 12 m in 30 s. If the mass of the elevator and passengers is 1000 kg, what is the power developed by the motor? 13. The efficiency of an incandescent light bulb is only 4.0%. Calculate the amount of electric energy that must be input to the bulb in order to get 100 J of light energy from the bulb. 14. Solve the following problem. Explain your reasoning throughout the solution. A student with a mass of 55 kg is sitting on a 5 kg toboggan at the top of a hill. The hill is 25 m high and is covered in very slippery snow. At the bottom of the hill is a parking lot covered in rough pavement. The student starts at the top of the hill and slides down to the bottom and out over the parking lot. She comes to a stop after skidding a distance of 16 m across the pavement. Calculate the force of friction from the pavement on the toboggan.