Question

A 3.0 kg rock is dropped from rest. What will its velocity be in 6.0 s if a 7.0 N force of air resistance acts on it?

Answer 1

14 m/s^2

Step-by-step explanation:

`v_(f)=V_(i) +at`

`V_(f)=`final velocity

`V_(i)=`initial velocity

a= acceleration

t=time

Initial velocity is zero, since the rock was originally at rest and time is 6 seconds.

You are looking for the final velocity, but you need acceleration to find it. Remember that:

`F=m*a`

Where F is force, m is mass, and a is acceleration. You know force is 7.0 N and mass is 3.0 kg. Use these to find a.

`7.0 N= 3*a`

`(7)/(3) = a`

So now...

`v_(f)=V_(i) +at`

`v_(f)=0 +((7)/(3)) (6)`

`v_(f)= 14 m/s^(2)`