A car, of total mass 1200 kg, is travelling at 90 km/h and strikes a tree. The front end of the car compresses and the driver comes to rest after travelling 0.80 m.

Question

(i)What was the average acceleration of the driver during the collision? Express the answer in terms of “g’s”.
(4 %)
(ii)How much energy was dissipated in the collision?

Answer 1

i) Is 4% your guess at the answer?

If a is the deceleration rate,
Vinitial = sqrt(2 a X)
Solve for a. Convert Vinitial to m/s first.
ii) ALL of the initial kinetic energy was dissipated.