As you throw a ball, you exert a force on that ball of 4.2 N. You exert this force on the ball while the ball moves a distance of 0.50 m. The ball then leaves your hand and travels a horizontal distance of 8.5 m to your friend. How much work have you done on the ball?

The work done is

Wd=2.1 joule

N/B work done is the product of force and the applied distance

Explanation:

We know that the work done expressed Mathematically as

Wd =F*d

Where Wd=work done

F=force exerted

d=distance within which the force was exerted

Given from the statement

Force =4.2N

Distance =0.5m

Note we did not use 8.5 m because the force was no longer in application

Hence

Wd=4.2*0.5

Wd=2.1 joule

think its the third option

f=ma newton's second law 7x8=56n