Question

A body of mass 5 kg is moving with a velocity of 10 m/s. A force is applied to it so that in 25 seconds, it attains a velocity of 35 m/s. Calculate the value of the force applied.

Answer 1

Here, mass, m = 5kg
Let us calculate the value of acceleration by using the first equation of motion,
Given that:
initial velocity, u = 10 m/s
final velocity, v = 35 m/s
time taken, t = 25 seconds
Putting these values in the equation, we get:
v = u + at
⇒ 35 = 10 + a × 25
⇒ 35 = 10 + 25a
⇒ 35 − 10 = 25a
⇒ 25 = 25a
$$\begin{gathered} \Rightarrow a=\frac{25}{25} \\ \Rightarrow a=1m/s^2 \end{gathered}$$
Now, putting m = 5 kg and a = 1 m/s² in equation we get,
Force = mass × acceleration
Force = m × a
Force = 5 × 1
Force = 5 N