Question

why a cricketer lower downs his hands while catching a ball

Answer 1

To reduce this force on the opposite direction the fielder lowers his hands ( which is in the direction of the balls original speed). Moving the hands in the direction of the ball's speed causes the ball to slow down first and then stop. ... So cricketer moves his hand backward while catching a ball.


Hope this helps you

Answer 2

It is due to inertia.
If he will not do this then he might hurt very badly.
Inertia is dependent on the Newton's 1st law.