Question

A 3.3 kg ball sits on the ground and is kicked with a FAPP of 36N

a) calculate Fg (gravity)
b) what is the net force
c) what is the balls acceleration

Answer 1

a) 32.3 N

The force of gravity (also called weight) on an object is given by

W = mg

where

m is the mass of the object

g is the acceleration of gravity

For the ball in the problem,

m = 3.3 kg

g = 9.8 m/s^2

Substituting, we find the force of gravity on the ball:

`W=(3.3)(9.8)=32.3 N`

b) 48.3 N

The force applied

`F_(app) = 36 N`

The ball is kicked with this force, so we can assume that the kick is horizontal.

This means that the applied force and the weight are perpendicular to each other. Therefore, we can find the net force by using Pythagorean's theorem:

`F=\sqrt{W^2+F_(app)^2}`

And substituting

W = 32.3 N

Fapp = 36 N

We find

`F=√(32.3^2+36^2)=48.3 N`

c)
`14.6 m/s^2`

The ball's acceleration can be found by using Newton's second law, which states that

F = ma

where

F is the net force on an object

m is its mass

a is its acceleration

For the ball in this problem,

m = 3.3 kg

F = 48.3 N

Solving the equation for a, we find

`a=(F)/(m)=(48.3)/(3.3)=14.6 m/s^2`