A | B |

After scoring a touchdown, an 84-kg wide receiver celebrates by leaping 120 cm off the ground. How much work is done in the celebration? | 987.84 J |

During a tug-of-war, Team A does 2.2 x 10^5 J of work by pulling Team b 8 m. What force is Team A exerting? | 27,500 N |

A weightlifter raises a 150-kg barbell to a height of 1.45 m. How much work is done by the weightlifter in lifting the barbells? | 2131.5 J |

A wagon is pulled by a force of 38 N on the handle at an angle of 42˚ with the horizontal. If the wagon is pulled in a circle of radius 25 m, how much work is done? | 4435.85 J |

A lawn mower is pushed with a force of 88 N along a handle that makes an angle of 41˚ with the horizontal. How much work is done in pushing the mower 1.5 km in mowing the yard? | 99,621.66 J |

A 15-kg crate is to be pulled a distance of 30 m, requiring 1280 J of work being done. If the job is done by attaching a rope and pulling with a force of 85 N, at what angle is the rope held? | 59.9˚ |

An elevator lifts a total mass of 1100 kg a distance of 40 m in 12.5 s. How much power does the elevator demonstrate? | 34,496 W |

A cyclist exerts a force of 15 N in riding a bike 251 m in 30 s. What is the cyclist's power? | 125.5 W |

Calculate the kinetic energy of a proton, mass 1.67 x 10^-27 kg, traveling at 5.20 x 10^7 m/s. | 2.26 x 10^-12 J |

What is the kinetic energy of a 3.2-kg pike swimming at 2.7 km/h? | 0.90 J |

A force of 30 N pushes a 1.5-kg cart, initially at rest, a distance of 2.8 m along a frictionless surface. Find the work done on the cart. What is the change in kinetic energy? What is the cart's final velocity? | 84 J; 84 J; 10.58 m/s |

A 712-kg car is traveling at 5.6 m/s when a force acts on it for 8.4 s, changing its velocity to 10.2 m/s. What is the change in kinetic energy of the car? | 25,874.08 J |

Five identical 0.85-kg books of 2.5-cm-thickness are each lying flat on a table. Calculate the gain in potential energy of the system if they are stacked one on top of the other. | 2.08 J |

A motorist whose car is out of gas pushes it at a steady speed of 0.75 m/s with a force of 200 N. What power does he deliver to the car? | 150 W |

What is the change in gravitational potential energy of a 1-kg mass that is carried from the surface of the Earth to a distance of one Earth radius above the surface? | 62,524,000 J |

A car engine develops 30 hp in moving the car at a constant speed of 50 mi/h. What is the average retarding force acting on the car? | 1001.5 N |

In a wild shot, Bo flings a pool ball of mass m off a 0.68-m-high pool table, and the ball hits the floor with a speed of 6.0 m/s. How fast was the ball moving when it left the pool table? | 4.76 m/s |

Kathy is changing the tire of her car on a steep hill 20.0 m high. She trips and drops the 10.0-kg spare tire, which rolls down the hill with an initial speed of 2.00 m/s. What is the speed of the tire at the top of the next hill, which is 5.00 m high? | 17.26 m/s |

A horizontal force of 50 N pushes a block along a level table at a constant speed of 4 m/s. How much work is done on the block in 8 s? | 1600 J |