Formula Review for Chapters 11 - 13 (Motion, Forces, Work, Energy) pg Formula Units Word Problem Solution 432 Work  ----------------------- W = F * D Joules 1)  How much work does a crane do if it uses a force of 5,200 Newtons to lift a girder 20 meters? 432 Work  ----------------------- W = m * g * D Joules 2) How much work is done if you are able to move a 5kg rock 20m? 433 Power    ----------------------- Power =   W                    T watts 3)  What is John's power output if he does 3,960 J of work in 120 seconds? 446 Potential Energy ----------------------- PE = m*g*h Joules 4)  What is the gravitational potential energy of a 1,200 kg car at the top of a hill that is 22 meters high? 463 Kinetic Energy ----------------------- KE = 1/2 mv2 Joules 5)  What is the kinetic energy of a 0.045 kg ball traveling at 4 m/s? 459 Efficiency = Wk Out / Wk In ----------------------- Eff = WO          WI % 6)  Alice and Jim calculate that they must do 1,800 J of work to push a piano up a ramp. However, they actually end up doing 2,600 J of work. What is the efficiency of the ramp? (lab) Acceleration  ----------------------- A =     2D            T2 m/s/s 7)  A ball bearing drops from 2 meters in 0.6442 seconds. What is its acceleration? 375 Acceleration  ----------------------- A =     FV - OV            T m/s/s 8) Natalie accelerates her skateboard along a straight path from 0m/s to 4.0 m/s in 4.5 s. Find her average acceleration. 369 Velocity    ----------------------- V = D       T m/s 9) A ball bearing rolls across the floor for 4 meters in 3 seconds. What is its velocity? 401 Force ----------------------- F = ma Newtons 10) A baseball that has a mass of 0.18kg accelerates downwards at 9.8 m/s/s. What is the gravitational force acting upon the baseball? 415 Momentum ----------------------- P = mv kg-m/s 11) Calculate the momentum of a 70 kg speed skater moving forward at 16 m/s