11.80. A particle moves along a straight line such that distance (x) traversed in t seconds is given by x = t2 (t - 4), the acceleration of the particle will be given by the equation

12.79. A body of weight W on inclined plane of a being pulled up by a horizontal force P will be on the point of motion up the plane when P is equal to

13.93. Kinetic friction is the

14.86. A projectile is fired at an angle 9 to the vertical. Its horizontal range will be maximum when 9 is

15.72. Which one of the following statements is not correct