Question

1. Which of the following regarding a collision is/are true? a. If you triple your speed your force of impact will be three times greater b. Speed has little effect on impact forces c. If you double your speed, the energy dissipated in a crash is four times greater d. If you double your speed, the energy dissipated in a crash is two times greater

Answer 1

Answer:

c

Explanation:

If you double your speed, the energy dissipated in a crash is four times greater

Because impact increases with square of increase in speed.

Answer 2

Answer:

c. If you double your speed, the energy dissipated in a crash is four times greater.

Explanation:

Given:

Impulse, P = force, f × time, t

= mass, m × velocity, v

Energy = kinetic energy, E = 1/2 × m × v^2

At v2 = 2v1

E1 = 1/2 × m × v1^2

= (m × v1^2)/2

E2 = 1/2 × m × (2v1^2)

= 1/2 × m × 4v1^2

= m × 2v1^2

(2 × E1)/v1^2 = E2/2v1^2

E1 = E2/4

E2 = 4 × E1