Question

A 1500 kg boxcar from a freight train is being shunted onto a siding at a speed of 3 m/s. Much like lazy customers returning a shopping cart in the parking lot, the conductor pushes the boxcar into the siding without looking, causing it to crash into a 1750 kg boxcar that is initially at rest.

What is the impulse given to the rest boxcar during the collision?

If the impact lasted for 40 milliseconds, what force was applied to the first boxcar?

Answer 1

Masses and

Initial velocity of first boxcar is and for second boxcar is

Both the boxcars move with same velocity after collision.(like shopping carts locking in )

Conserving momentum of two boxcars before and after collision,

Impulse given to the rest boxcar during collision is

Time lasted for impact

Impulse on the first boxcar

(negative sign indicates its direction which is opposite to initial direction of motion)

Magnitude of force is