A handheld launcher of mass 2.5 kg rests on a low-friction cart
PHYSICS · Multi-part · CBSE · Physics · Laws of Motion · Laws of Motion
Problem
A handheld launcher of mass 2.5 kg rests on a low-friction cart. From rest, it fires a 15 g foam dart horizontally. The dart emerges from the barrel with a speed of 12 m/s relative to the ground.
(a) Determine the speed of the launcher immediately after the dart leaves the barrel and is no longer in contact with it.
(b) Inside the barrel the dart travelled 0.30 m while accelerating uniformly. Calculate the magnitude of the average force exerted by the dart on the launcher during this time.
(c) In a second trial the dart leaves the barrel at 18 m/s. Predict qualitatively—without calculation—whether the magnitude of (i) the launcher’s recoil speed, (ii) the impulse delivered to the launcher, and (iii) the launcher’s kinetic energy will each increase, decrease, or stay the same compared with the first trial. Justify each prediction briefly.