Kinematics Question 234
Question: A very large number of balls are thrown vertically upwards in quick succession in such a way that the next ball is thrown when the previous one is at the maximum height. If the maximum height it’s 5m, the number of ball thrown per minute it’s (take $ g=10m{{s}^{-2}} $ ) [KCET 2002]
Options:
A) 120
B) 80
C) 60
D) 40
Show Answer
Answer:
Correct Answer: C
Solution:
Maximum height of ball = 5 m So velocity of projection
$ \Rightarrow $ $ u=\sqrt{2gh} $
$ =10\ m/s $ Time interval between two balls (time of ascent) $ =\frac{u}{g}=1\ sec=\frac{1}{60}min $ . So number of ball thrown per min. = 60
