3. On the earth, a stone is thrown from a height in a direction parallel to the earth surface while another stone is simultaneously dropped from the same height. Which stone would reach the ground first and why? 4. A hammer of mass 500gm moving at 50 m/s strikes a nail .The nail stops the hammer in a very short time of 0.01sec. What is the force of nail on the hammer? 5. A man throws a ball of mass 500 gm vertically upwards with a velocity of 25 m/sec. Find a) The initial momentum of the ball. b) Momentum of the ball at the half way mark of the maximum height. (g=10 m/s2 ) 6. Derive the relation between force and acceleration using second law of motion. A bullet of log strikes a sand bag at a speed of 103 m/s and gets embedded after travelling 5 cm. Calculate: i) The resistive force exerted by the sand in the bullet. ii) The time taken by the bullet to come to rest.