Question

A 2,000-kg car traveling at 40 m/s hits a wall with a force of 40,000 N and comes to a stop. What was the impact time?

Answer 1

If I did my math correct, the answer would be 2 seconds.

Answer 2

The impact time is equal to
`2` seconds

Step-by-step explanation:

Given -

Force (F)
`= 40,000` N or
`(Kg-m)/(s^2)`

Mass(M)
`= 2,000` Kg

Initial Velocity (u)
`= 40(m)/(s)`

Final Velocity (v)
`= 0(m)/(s)`

Force exerted by any body is equal to the product of its mass and acceleration

Hence, mathematically it can be represented as

`F = M * a`

Substituting the given values, we get -

`40,000 = 2,000 * a\\a = 20 (m)/(s^2)`

As per Newton's first law of motion,

`v = u - at` in case of deceleration

Substituting the available values in above equation, we get -

`0 = 40 - 20 * t\\40 = 20*t\\t = (40)/(20) \\t = 2` seconds

The impact time is equal to
`2` seconds