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

The speed of the car is 18.75 m/s

Step-by-step 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=(J)/(m)+v_1`

Substituting:

`\displaystyle v_2=(-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