21.A particle is moving on a straight line path with constant acceleration directed along the direction of instantaneous velocity. Which of following statements are false about the motion of particle?

22.Six persons are initially at the six corners of a hexagon of side a. Each person now moves with a uniform speed v in such a manner that 1 is always directed towards 2, 2 towards 3, 3 towards 4 and so on. The time after which they meet is:

23.Which of the following statements is correct?

24.A particle starts with a velocity of 2 m/s and moves in a straight line with a retardation of 0.1 m/second square. The time that it takes to describe 15m is:

25.Balls are thrown vertically upward in such a way that the next ball is thrown when the previous one is at the maximum height. If the maximum height is 5m, the number of balls thrown per minute will be: (Take g = 10 m/second square)