Physics Assignment Help: How much work is done moving a...

Q)How much work is done moving a 2.5 kg book to a shelf 3.0 m high?

a.What is the potential energy of the book in #7 above?
b.If the book in #7 above, falls off the shelf, how much kinetic energy will it have when it hits the floor

Sol:

Work done = Force*displacement

Force=m*g=2.5*9.8=24.5N

Work done= 24.5*3=73.5Joules

a) Potential energy = work done= m*g*h= 73.5Joules

b) Kinetic energy when it hits the floor will be at t=0,

V=U + at=0+9.8*0=0

KE= ½*m*v² = 0J