An automobile of mass 1.2 ,× ,10^3 kg is traveling due north on a straight
PHYSICS · Multi-part · CBSE · Physics · Laws of Motion · Laws of Motion
Problem
An automobile of mass 1.2\,×\,10^3 kg is traveling due north on a straight, level road at a constant 15 m/s when the driver turns off the engine so that no further propulsion is supplied. Air resistance and rolling resistance are negligible unless otherwise stated.
(a) Assuming the net horizontal force on the car becomes zero immediately after the engine is turned off, determine the distance the car travels in the next 10 s.
(b) In a more realistic situation a constant drag force of 200 N acts opposite the car’s motion as soon as the engine is shut down. Calculate (i) the magnitude of the car’s acceleration and (ii) the distance the car travels in the same 10 s interval under this drag force.
(c) Compare your answers from parts (a) and (b). Explain how the presence or absence of a net force accounts for any differences in the car’s motion.