You hold a metal block of mass 40 kg above your head at a height of 2 m.
how much work is done by gravity if you let the block fall to the ground?
o a. -80 j
o b. 80
o c. 784 j
o d. -784

The work done by gravity is 784 J.

Explanation:

Given:

Mass of the block is,

Height to which it is raised is,

Acceleration due to gravity is,

Now, work done by gravity is equal to the product of force of gravity and the distance moved in the direction of gravity. So,

Force of gravity is given as the product of mass and acceleration due to gravity.

. Now,

Therefore, the work done by gravity is 784 J.

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

speed = 20/2 = 10 m/s