What is the change in momentum of a 50-kg rock that falls freely for 3 seconds?

1470kgm/s

Explanation:

Given parameters:

Mass of the rock = 50kg

Time taken for the free fall  = 3s

Unknown:

Change in momentum = ?

Solution:

The change in momentum will be difference between the ending momentum and finishing momentum.

  Momentum is the product of mass and velocity

       Momentum  = mass x velocity

Initial momentum  = 0, the velocity is 0

Final momentum = mass x final velocity

      let us find the final velocity;

                V = U + gt

V is the final velocity

U is the initial velocity

g is the acceleration due to gravity = 9.8m/s²

t is the time

                 V  = 0 + 9.8x3 = 29.4m/s

So;

 Change in momentum  = 50 x 29,4  = 1470kgm/s

second mirror gathers light from a faraway object and reflects it to another mirror. - a.

what is the speed of a softball that travels 20m in 2secs

speed = 20/2 = 10 m/s