Question

A. Car travels 18 m/s and hits a concrete wall. Driver = 90 kg. Find the change in momentum of the driver.

B. What impulse produces this change in momentum?

Answer 1

Given:

Car travels 18 m/s and hits a concrete wall. Driver = 90 kg.

To find:

Change in momentum of car & Impulse ?

Calculation:

Impulse is same as change in momentum , it refers to a quantity which describes for how much time the force was applied to an object to cause a change in momentum.

Let impulse be I and change in momentum be ∆P.

$\therefore \: I = \Delta P = m\Delta v$

$\implies \: I = 90 \bigg(0 - 18 \bigg)$

$\implies \: I = 90 \times \bigg( - 18 \bigg)$

$\implies \: I =\Delta P = - 1620 \: kgm {s}^{ - 1}$

So, the impulse or change in momentum is -1620 kgm/s.

However , if the question asks about momentum transferred to the wall , the answer will be +1620 kgm/s.