A ball falls vertically after being dropped. It falls 20 metres in a time of 2 seconds. If 'd' is the distance in meters and t (in seconds) is the time taken where d is directly proportional to the square of t, how much time the ball will take to fall 605 m?
11
Given distance s is directly proportional to square of time t.
That is:
s=k.t220=4kk=5So,s=5t2605=5t2
t = 11 seconds