When you peel some sticky tape from a roll it often tries to go back on again. Explain, as fully as you can, why it does this.

Name two kinds of practical electric pumps.

Two cannon balls weighing 18 kg and 24 kg are chained together and fired horizontally with a velocity of 165 m/s from the top of a 21-m wall. the chain breaks during the flight of the cannonballs and the 18-kg cannonball strikes the ground at t = 1.5 s, at a distance of 240 m from the foot of the wall, and 7 m to the right of the line of fire. determine the position of the other cannonball at that instant. neglect the resistance of the air.

What is the quantity which is measured by the area occupied below the velocity- time graph?