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 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

2. 1,920 ft-lb 1,921 ft-lb 2,020 ft-lb 1,870 ft-lb 1,769 ft-lb
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 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

3. An aquarium 3 m long, 8 m wide, and 1 m deep is full of water
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 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

4. 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} 1. 2. 3. 4. 5. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

5. 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} 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} N {image} m 2 / kg 2. Round the answer to the nearest million. 1. 2.
{image} 3. 4. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50