Momentum & Impulse Practice
A 2,000 kg car uses a braking force of 12,000. N to stop in 5.00 seconds.
a.) What is the impulse?
b.) What is the change in momentum of the car? CHANGE IN MOMENTUM = 60,000 Ns c.) What was the initial speed of the car?
2,000 2,000 |
Explanation
After reading the data I was given from the problem, I was able to determine what formula would work best. I was given the force and time of the car's break. By multiplying these two numbers, I was able to see that the impulse was 60,000 Ns. The next question was directly connected to the first. The change in momentum is equal to the impulse, meaning that the change in momentum was also 60,000 Ns.
Before solving the next question, I listed my variables: - J = 60,000 Ns - Velocity 2 = 0 m/s (comes to a stop) - Mass 1 = 2,000 kg - Mass 2 = 2,000 kg I had to solve for the initial velocity so I used the formula - J = M1V1 - M2V2 Next I plugged in my variables and divided by 2,000 kgs on both sides of the equation in order to get (x) alone. After doing this, I was left with the solution to the problem. X = 30 m/s |