Question

How fast will an object with a mass of `15 kg` accelerate if a force of `72 N` is constantly applied to it?

Answer 1

The acceleration is `4.8 m/s^2`.

Explanation:

The formula that describes the relationship discussed in Newton's 2nd Law is

`F = m*a`.

To find acceleration when knowing force and mass, we need to do some algebra on the above formula. Divide both sides by m and cancel where possible.

`F/m = (cancel(m)*a)/cancel(m)`
So
`a = F/m`

If we plug your data into that equation and perform the indicated division, we find that

`a = F/m = (72 N)/(15 kg) = 4.8 N/(kg)`

The usual units for acceleration are `m/s^2`.
`N/(kg)` does not look so much like acceleration.
But, if we look at `F = m*a` we will see that 1 Newton, applied to a mass of 1 kg, will cause acceleration of 1 m/s^2. So the Newton is equivalent to `(kg*m)/s^2`. That combination of units was named the Newton to honor Isaac.

Therefore,

`a = F/m = 72 N/15 kg = 4.8 N/kg = 4.8 m/s^2`

I hope this helps,
Steve

Answer 2

`4.8 \ "m/s"^2`

Explanation:

We use Newton's second law of motion here, which states that

`F=ma`

where `m` is the mass of the object in kilograms, `a` is the acceleration of the object in `"m/s"^2`, and `F` is the force acting on the object in newtons.

We need to solve for acceleration, so we can rearrange the equation into

`a=F/m`

Now, plugging in the given values, we get

`a=(72 \ "N")/(15 \ "kg")`

`=4.8 \ "m/s"^2`

So, the object's velocity will keep increasing by `4.8 \ "m/s"` every second towards the direction of the force applied.