A freight wagon of unknown mass is moving westward along a straight track
PHYSICS · Subjective · CBSE · Physics · Laws of Motion · Laws of Motion
Problem
A freight wagon of unknown mass is moving westward along a straight track. Instruments show its linear momentum to be 4.05×105Ns directed due west. At that instant a speedometer fixed to the wagon reads 108kmh−1.
(a) Convert the quoted speed into metres per second.
(b) Determine the mass of the wagon.
(c) The brakes are applied so that the speed becomes 54kmh−1 while the wagon continues westward. Calculate the magnitude of the change in the wagon’s momentum during this braking period.
(d) Comment briefly on how the direction of momentum has been affected, if at all.