Question

A 2,000-kg test car, traveling 60 m/s hits a brick wall. Using motion pictures, the time involved is determined to be 0.050 s. What is the change in momentum of the car?
A) +1.2 x 10^5

B)-1.2 x 10^5

Answer 1

change in momentum of car is given as

$\Delta P = P_f - P_i$

here we have

$\Delta P = m(v_f - v_i)$

given that

m = 2000 kg

$v_f = 0$

$v_i = 60 m/s$

now we have

$\Delta P = 2000(0 - 60)$

$\Delta P = - 1.2 \times 10^5 kg m/s$