Question

dummy jimmy is stopped with a cement wall, while dummy casey is stopped with an airbag. both dummies have the same mass. during a car collision test, two crash test dummies are given a velocity of 27 m/s, and then brought to a stop. which dummy has a higher impulse applied to him?

Explanation:

Step1: Recall the impulse - momentum theorem

The impulse - momentum theorem states that \(J=\Delta p = m(v - u)\). Both dummies have the same mass \(m\) and initial velocity \(u = 27\ m/s\), and final velocity \(v = 0\ m/s\).

Step2: Calculate the impulse for each dummy

For Dummy Jimmy: \(J_{Jimmy}=m(0 - 27)=- 27m\). For Dummy Casey: \(J_{Casey}=m(0 - 27)=- 27m\). The magnitude of the impulse is \(|J| = 27m\) for both dummies. The negative sign just indicates the direction of the impulse (opposite to the initial velocity direction).

Answer:

They have the same impulse.