Formula Review for Chapter 13 -- With Solutions pg Formula Units Word Problem Solution 432 Work W = F * D Joules 1) A crane uses an average force of 5,200 N to lift a girder 25 m. How much work does the crane do on the girder? 433 Power Power = W / T Power = (F*D)/T watts 2) Ann walks up the stairs on her way to class. She weighs 565 N and the stairs go up 3.25 m vertically. If she climbs the stairs in 12.6 seconds, what is her power output? 446 Potential Energy PE = m * g * h Joules 3) What is the gravitational potential energy of a 0.52 kg bird flying at an altitude of 550 m? 463 Kinetic Energy KE = 1/2 m* v2 Joules 4)What is the kinetic energy of a 0.45 kg ball traveling at 2 m/s? 459 Efficiency Eff = WO / WI % 5) Alice and Jim calculate that they must do 1500 J of work to push a desk up a ramp. They actually use 2500 J of work. What is the efficiency of the ramp? (lab) Acceleration A = 2D / T 2 m/s/s 6) A ball bearing drops from 2 meters to the ground in 0.6388 seconds. What is its acceleration? (lab) Velocity V = D / T m/s 7) A ball rolls across the floor for 5 meters in 3 seconds. What is its velocity?