Force: Newton's Law of Motion
Important Question Answer (Chapter Revision); Ready to Test your knowledge Q1. Why does the electric fan continue to rotate for sometime after the current is switched off.? Ans. The fan continues to rotate due to inertia of motion, until the friction in bearings and that of air brings it to rest. Q2. Is a train moving on a circular track, an inertial frame of reference.? Ans. No Q3. A trolley of mass 300kg carrying a sand bag of 25kg is moving at a uniform speed of 27km/h on a smooth track. After a while, sand begins to leak out of a hole on the trolleys floor at a rate of 0.05kg/s. What is the speed of the trolley after the entire sand bag is empty.? Ans. As the trolley is moving uniformly on a smooth track, no external forces acts on the trolley bag system. Hence its speed will remain 27km/h even after the bag become empty through leakage of sand. Q4. A Bob of mass 0.1kg hung from the ceiling of a room by a string 2m long is set into oscillation. T...