Question

a car with a mass of 1.2 × 103 kilograms is moving at a speed of 18 meters/second. It is hit by a truck from behind and its speed after the collision increases to 20 meters/second. What is the value of impulse?

Answer 1

Answer: Value of impulse is $2.4\times 10^3\text{kg m/s}$

Explanation: lmpulse is defined as the amount of force acting over a short time interval 't' which is equal to the change in momentum of the body having mass 'm'.

Mathematically,

$J=F\times t=m\Delta v$

And,

$\Delta v=v_2-v_1$

Given:

$m=1.2\times 10^3kg\\v_1=18m/s\\v_2=20m/s$

Putting values in above equation, we get:

$J=m(v_2-v_1)=1.2\times 10^3(20-18)\text{ kg m/s}$

$J=2.4\times 10^3\text{kg m/s}$

Answer 2

2.4 × $10^{3}$ kilogram meters/ second