A car weighing 1600 kg moving with a velocity of 30 m/s retards uniformly coming to rest in 2 seconds . Calculate the
(i) Initial and final momentum of the car
(ii) Rate of change of momentum of the car .
(iii) Acceleration of the car .

Explanation

Given , m = 1600 kg, u = 30 m/s , `Deltat = 20 s , v = 0 `
(i) Initial momentum = `P_(i) = "mu" = 1600 xx 30 "kg" m//s = 48 xx 10^(3) "kg" m//s`
Final momentum = `P_(f) = "mv" = 0 `
(ii) Rate of change of momentum , ` F= (P_(f)-P_(i))/(Deltat)`
` = (0- 48 xx 10^(3))/(20 s) ` kg m/s
` 2*4 xx 10^(3) N`
(iii) Acceleration of the car , ` a = F/m = (2.4 xx 10^(3) N)/(1600 kg) = -1*5 m//s^(2)`