Question

A force of 16N acts on a body of mass 90 kg for 2 min, if the body is initially at rest, the final velocity isA. 20.36 ms^- 1 B. 21.36 ms^- 1C. 22.36 ms^- 1D. 23.36 ms^- 1

Answer 1

21.33 m s^-1

Step-by-step explanation:

To find the final velocity, we will use the equation for impulse, so

`I=Ft=mv_f-mv_i`

Where F is the force, t is the time, m is the mass, vf is the final velocity and vi is the initial velocity. We know that

F = 16 N

t = 2 min = 120 s

m = 90 kg

vi = 0 m/s

vf = ?

Solving for vf, we get:

`\begin{gathered} Ft+mv_i=mv_f \\ \\ v_f=(Ft-mv_i)/(m) \end{gathered}`

Then, we can replace the values to get

`\begin{gathered} v_f=\frac{(16\text{ N\rparen\lparen120 s\rparen- \lparen90 kg\rparen\lparen0 m/s\rparen}}{90\text{ kg}} \\ \\ v_f=\frac{1920\text{ kg m/s}}{90\text{ kg}} \\ \\ v_f=21.33\text{ m/s} \end{gathered}`

Therefore, the answer is

21.33 m s^-1