Light gates may be used to measure the speed of projectiles, such as arrows shot from a bow. English longbows made of yew in the 1400s achieved launch speeds of 60m/s. Determine the relationship between the distance between light gates and the accuracy required for sensing the times when the light gate senses the presence of the arrow.

Aballoon is rising vertically upwards at a velocity of 10m/s. when it is at a height of 45m from the ground, a parachute bails out from it. after 3s he opens his parachute and decelerates ata a constant rate 5m/s.when. (a) what was the height of the parachutist above the ground when he opened his parachute? (b)how far is the parachutist from the balloon at t=3s? (c)with what velocity does the parachutist hit the ground? (d)after how long does the parachutist hit the ground after his exist from the balloon?