Question

What is the net force acting on a falling 1-kg ball if it encounters 2N of air resistance?

Answer 1

`color(green)("Net Force"=-7.8"N")`

Explanation:

Start by computing for the weight of the ball.

`[1]color(white)(XX)w=mg`

`[2]color(white)(XX)w=(1"kg")(9.8"m/s"^2)`

`[3]color(white)(XX)w=9.8"kg"*"m/s"^2`

`[4]color(white)(XX)color(red)(w=9.8"N")`

Now let's create a diagram representing the forces acting on the ball:

`color(white)(XX)BALL`
`darrcolor(red)(9.8"N")` `uarrcolor(blue)(2"N")`

Simply add the two forces together to get the net force. The weight `color(red)(9.8"N")` is negative since it is directed downwards, while the air resistance `color(blue)(2"N")` is positive since it is directed upwards.

`"Net Force"=color(red)(-9.8"N")+color(blue)(2"N")`

`color(green)("Net Force"=-7.8"N")`