1. A weight lifter lifts a set of weights a vertical distance of 3.85 m. If a constant net force of 350 N is exerted on the weights, what is the net work done on the weights? (Show all work and include units of measure)

2. A car has a kinetic energy of 4.32 x 10^5 J when traveling at a speed of 23 m/s. What is its mass? (Show all work and include units of measure)

3. A student wearing frictionless in-line skates on a horizontal surface is pushed by a friend with a constant force of 45 N. How far must the student be pushed, starting from rest, so that her final kinetic energy is 352 J? (Show all work and include units of measure)

Help me please

1 answer

1. work = force * distance

2. K.E. = 1/2 * m * v^2 ... m = 2 * K.E. / v^2

3. same as 1 ... work and energy are equivalent ... distance = K.E. / force