Question

A car of mass 1100 Kg drives with a velocity such that it has a kinetic energy of 400 kJ ( see the Figure). Find the velocity. If the car is raised with a carne how high should it be lifted in the standard gravitational field (9.81 m/s2) to have a potential energy that equals the kinetic energy?

Answer 1

(i)
KE = m * V^2 / 2
V = sqrt(2 * KE / m)
V = sqrt(2 * 400000 / 1100) =
26.968 m/s
(ii)
PE = m * g * h. If PE = KE,
h = KE / (m * g)
h =
400000 / (1100 * 9.81) = 37.068 m