INTRODUCTORY EXERCISE 7 2 1 A particle is projected from ground with velocity 40 2 m s at 45 Find a velocity and b displacement of the particle after 2 s g 10 m s 2 Under what conditions the formulae of range time of flight and maximum height can be applied directly in case of a projectile motion 3 What is the average velocity of a particle projected from the ground with speed u at an angle a with the horizontal over a time interval from beginning till it strikes the ground again 4 What is the change in velocity in the above question 5 A particle is projected from ground with initial velocity u 20 2 m s at 0 45 Find a R H and T b velocity of particle after 1 s c velocity of particle at the time of collision with the ground x axis 6 A particle is projected from ground at angle 45 with initial velocity 20 2 m s Find a change in velocity b magnitude of average velocity in a time interval from t 0 tot 3 s Fig 7 14 7 The coach throws a baseball to a player with an initial speed of 20 m s at an angle of 45 with the horizontal At the moment the ball is thrown the player is 50 m from the coach At what speed and in what direction must the player run to catch the ball at the same height at which it was released g 10 m s 8 A ball is thrown horizontally from a point 100 m above the ground with a speed of 20 m s Find a the time it takes to reach the ground b the horizontal distance it travels before reaching the ground c the velocity direction and magnitude with which it strikes the ground 9 A bullet fired at an angle of 30 with the horizontal hits the ground 3 0 km away By adjusting its angle of projection can one hope to hit a target 5 0 away Assume the muzzle speed to be fixed and neglect air resistance 10 A particle moves in the xy plane with constant acceleration a directed along the negative y axis The equation of path of the particle has the form y bx cx where b and c are positive constants Find the velocity of the particle at the origin of coordinates