Question

21. A ball dropped from a point P crosses a point Q in t seconds. The time taken by it to travel from
Q to R if PQ = QR​

Answer 1

Answer:

Since in the question the distance PQ and QR is same then let that distance be d or PQ=QR=d.

Then from Newtons laws of motion we will get that x=1/2gt^2−(1)

Again,  2x=1/2gt1^2−(2)  for the total distance covered.

If the equations (1) and (2) are divided then we will get that,

1/2=t^2 / t1^2 which will be equal to t1=t√2.

Hence, from then Q to R the time taken will be t1−t=t√2−t=t(√2−1)

Answer 2

according to the question answer is given