Question

A 1600 kg car is moving north with a speed of 25 m/s. An impulse of 10,000 N-s south is applied to the car. After the impulse is applied, the speed of the car is:

Answer 1

Answer:

The speed of the car is 18.75 m/s

Explanation:

Impulse-Momentum Change Equation

The impulse received by an object is equal to the change in momentum:

Impulse = Change in momentum

The change in momentum is:

$\Delta p=m\Delta v=m(v_2-v_1)$

Where m is the mass of the object, v2 is the final speed, and v1 is the initial speed. This means the impulse J is:

$J=m(v_2-v_1)$

It's given an m=1,600 kg car is moving at v1=25 m/s North and then an impulse of J=-10,000 N.s is applied South. The minus sign indicates the impulse is opposite to the original direction of the velocity.

Solving for v2:

$\displaystyle v_2=\frac{J}{m}+v_1$

Substituting:

$\displaystyle v_2=\frac{-10,000}{1,600}+25$

$\displaystyle v_2=-6.25+25=18.75$

$v_2=18.75\ m/s$

The speed of the car is 18.75 m/s