Question

What is the least velocity with which a cricket ball can be thrown through a distance of 100m

Answer 1

Answer:

It depends.

Explanation:

The distance a body travels when projected depends almost exclusively on the height from which it is projected. It is the downward acceleration of earth which pulls down objects. A projected ball will stop travelling horizontally only if it touches ground and all the distance it covers in the mean time depends on the time it was in air. This cannot be known if the height is unknown.

Now if the height was known, then one can easily calculate the time for it to hit the ground. Now as the velocity of projection is supposed to be minimum, then the object must be projected horizontally with no inclination, the horizontal velocity must be sufficiently high that it covers 100m in the time of flight.  

Time of flight is found by s=ut+1/2*g*t^2

     =>  t = sq.root(2s/g) , as u=0(because we are projecting it horizontally. The minimum velocity say 'v' is given by

v*t=100.

v=100/t.