A 2,200-kg pile driver is used to drive a steel I-beam into the ground. The pile driver falls 4.00 m before coming into contact with the top of the beam, and it drives the beam 15.2 cm farther into the ground as it comes to rest. Using energy considerations, calculate the average force the beam exerts on the pile driver while the pile driver is brought to rest.  ?=magnitude direction= ?

A 2,200-kg pile driver is used to drive a steel I-beam into the ground. The pile driver falls 4.60 m before coming into contact with the top of the beam, and it drives the beam 15.0 cm farther into the ground as it comes to rest. Using energy considerations, calculate the average force the beam exerts on the pile driver while the pile driver is brought to rest. 588925.42 magnitude Write an expression for the work done by all of the forces acting on the beam as it moves into the ground and relate that work to the change in energy of the pile driver in order to find the force that the beam exerts on the pile driver. N

2 W S X In a hydroelectric dam, water falls 35 m and then spins a turbine to generate electricity. 3 E D 80 C $ 4 R 888 F V 96 5 T G ^ 6 B ▾ Part A What is AU of 1.0 kg of water? Express your answer with the appropriate units. View Available Hint(s) AU= -340 J Y Submit ▾ Part B ✓ Correct SOLVE: The change in the potential energy of 1.0 kg of water in falling 35 m m is H Suppose the dam is 80% efficient at converting the water's potential energy to electrical energy. How many kilograms of water must pass through the turbines each second to generate 48 MW of electricity? This is a typical value for a small hydroelectric dam. Express your answer in kilograms per second. ▸ View Available Hint(s) m 11s AU, -mgh=-(1.0 kg) (9.8 m/s²) (35 m) = -340 J = = Provide Feedback Submit MacBook Air Previous Answers & 7 N IG] ΑΣΦ | 3-4 U * 8 D-H I M @ JK ( 9 MOSISO DD O I भ ? O L kg/s command F10 P > ; C option + ? T I Next > delete re

The concepts in this problem are similar to those in Multiple-Concept Example 4, except that the force doing the work in this problem is the tension in the cable. A rescue helicopter lifts a 90.5-kg person straight up by means of a cable. The person has an upward acceleration of 0.512 m/s2 and is lifted from rest through a distance of 8.89 m. (a) What is the tension in the cable? How much work is done by (b) the tension in the cable and (c) the person's weight? (d) Use the work-energy theorem and find the final speed of the person.