3. A lifting machine lifts a load of 1000N through a distance of 0.2 m by means of an effort of 200N through a distance of 1m. This machine is an ideal one.
8. Two blocks A and B of masses 150 kg and 50 kg respectively are connected by means of a string as shown in the below figure. The tension in all the three strings __________ be same.
9. In collision of elastic bodies, the coefficient of restitution is the ratio of the relative velocity after impact to the relative velocity before impact.