1. (6p) If the work required to stretch a spring 3 ft beyond its natural length is 15 ft-lb, how much work (in ft-lb) is needed to stretch it 18 in. beyond its natural length? Give your answer in decimal form.

A different car accelerated from 0.12 m/s to 0.52 m/s. The acceleration of the car was 0.040 m/s². The work done to accelerate the car was 0.48 J. Calculate the resultant force needed to accelerate the car.

4. A car crashes into a tree. What is the work done by the tree stopping the car? The car has a mass of 2075 kg and was traveling at 20.45 m/s. Include a negative if appropriate. Previous submissions:

The average hp required to raise a 150000x10^-3 kg box a height of 65.6168 ft over a period one minutes is what?

4. A spring has a natural length of 9 inches and a force of 7 Ibs is required to stretch and hold the spring to a length of 21 inches. What is the work required to stretch the spring from a length of 12 inches to a length of 30 inches? A cabie 13

2) What is the work done by the force of gravity Fg ? A. F dcos(0) B. F dcos(90) C. F dcos(180") D. F dcos(270) F. 3)

4. How much is the work done in pulling up a block of wood weighing 300 N for a length of 300 cm on a smooth plane inclined at an angle of 35° with the horizontal ? Answer = ENG DELL F5 F6 F7 F8 F1 F2 F3 F4 & @ $. E & DI FI

2. Nicole lifts a bowling ball with a mass of 6.2 kg to a height of 1.5 meters above the floor. (a) How much work does she do to lift it? [be careful! E-S-AJ (b) How much gravitational potential energy (GPE) does the ball now have relative to the floor? (E-S-AJ (c) Work put into lifting an object to a given height is (greater than, less than, equal to) the GPE of the object as it rests at that height. (d) How much kinetic energy (KE) does the ball have as she holds it at rest at this height? while increasing in (height. (e) If she drops the ball, the ball will decrease in (height, speed) This indicates a transference of (KE, GPE) to (KE, GPE) speed)

3. You lift a book of mass 2 kg at constant speed straight upward a distance of 2 m. How much work is done during this lifting by you?

A 62 kg man climbs the CN tower which is 0.55 km high in 30 min. How powerful is the man?    a) 1.9 X 10¹ W   b) 1.9 X 10² W   c) 1.1 X 10⁴ W   d) 1.9 X 10⁻¹ W