Question

A mass of 10 kg, initially at rest on a horizontal frictionless surface, is acted upon by a horizontal force of 25 N. The speed of the mass after it has moved 5.0 m is:

Answer 1

We will have the following:

`\begin{gathered} W\ast d=(1)/(2)mv_f^2-(1)/(2)mv_i^2 \\ \\ \end{gathered}`

Then, we will have that:

`\begin{gathered} (25N)(5m)=(1)/(2)(10kg)v_f^2-(1)/(2)(10kg)(0m/s){}2 \\ \\ \Rightarrow125N\ast m=(5kg)v_f^2\Rightarrow v_f^2=(25N\ast m)/(kg) \\ \\ \Rightarrow v_f=5m/s \end{gathered}`

So, the final velocity of the mass after it has moved 5 meters is 5m/s.