Question

Dr. Melville’s car (mass = 1500 kg) dies on him when he is travelling 20 m/s at the bottom of a hill. Ignoring friction and air resistance, the maximum increase in gravitational potential energy he can experience is…

A. less than 100000 J                       B. equal to 100000 J    

C. greater than 100000 J                 D. Impossible to determine

Explain your reasoning

Answer 1

mass =m = 1500 kg

at the bottom speed =20 m/sec and height h = 0 m

   at maximum height speed = 0 m/sec,   H = maximum

    from conservation energy

       energy at bottom = energy at top

               1/2 m V^2 = maximum potential energy

             maximum potential energy = 1/2 * 1500 * 20^2 = 300000 J

          grater than 100000 J