Use the Impulse-Momentum Theorem

[Raimuna]

Homework Statement

Use the impulse-momentum theorem to find how long a stone falling straight down takes to increase its speed from 4.8 m/s to 10.7 m/s.

I really don't get the question. How could we find the time in second if we only know the initial and final velocity.

Homework Equations

The Attempt at a Solution

 

[Redbelly98]

I really don't get the question. How could we find the time in second if we only know the initial and final velocity.

I am going to consider this an attempt at a solution, and offer a hint: You also know the acceleration.

Also, the impulse-momentum theorem is definitely a relevant equation here.

 

[Raimuna]

How do we find the acceleration if we don't know the time interval?

 

[denverdoc]

Force*time=m(Vf-Vi) solve for time. Force is obviously gravity=mg