True False

1. True or False: If a force of 6 lbs is required to hold a spring stretched 5 inches beyond its natural length, then 60 lb-in. of work is done in stretching it from its natural length to 10 in. beyond its natural length. • True • False

2. A heavy rope, 80 ft long, weighs 0.6 lb/ft and hangs over the edge of a building 140 ft high. How much work is done in pulling the rope to the top of the building? • 1,920 ft-lb • 1,921 ft-lb • 2,020 ft-lb • 1,870 ft-lb • 1,769 ft-lb

3. An aquarium 3 m long, 8 m wide, and 1 m deep is full of water. Find the work needed to pump half of the water out of the aquarium. (Use the facts that the density of water is {image} and {image} .) • 29,250 J • 29,411 J • 29,400 J • 28,400 J • 29,410 J

4. 1. 2. 3. 4. 5. When gas expands in a cylinder with radius {image} , the pressure at any given time is a function of the volume: {image} . The force exerted by the gas on the piston ( see the figure ) is the product of the pressure and the area: {image} Find the work done by the gas when the volume expands from volume {image} to volume {image} {image} • {image} • {image} • {image} • {image} • {image}

5. 1. 2. 3. 4. Use Newton's Law of Gravitation to compute the work required to launch a 1,600 - kg satellite vertically to an orbit 1,100 km high. You may assume that Earth's mass is 5.98 {image} 10 24 kg and is concentrated at its center. Take the radius of Earth to be 6.37 {image} 10 6 m and G = 6.67 {image} 10 - 11 N {image} m 2 / kg 2. Round the answer to the nearest million. • {image} • {image} • {image} • {image}