Question

a body of mass 250g is moving with a velocity of 20m/s. A force is applied on that body for 2 second, then the velocity of body becomes 30m/s. find out the magnitude of force applied?​

Answer 1

$\huge\mathfrak{Answer}$

$\sf 1.25 \ N$

$\huge\mathfrak{Explanation}$

Here, we are given :-

mass (m) = 250 g = 0.25 kg

initial velocity (u) = 20 m/s

final velocity (v) = 30 m/s

time (t) = 2 seconds.

From Newton's second law, we know that

F = ma

and, a = (v - u)/t

So, we can write, F = m(v - u)/t

So, now just substitute the respective values to get the answer.

F = 0.25(30 - 20)/2

⇒ F = 0.25(10)/2

⇒ F = 0.25 × 5

⇒ F = 1.25 N

$\rule{200}2$

Answer 2

Answer-

Initial velocity (u) = 20 m/s

Final velocity (v) = 30 m/s

Time (t) = 2 secs

Mass of body (m) = 250 g = 0.

Now,

$\sf Acceleration=\frac{v-u}{t}\\\\\sf a=\frac{30-20}{2}\\\\\sf a= \frac{10}{2}\\\\\bf a=5\:ms^{-2}$

We know that;

Force = Mass * Acceleration

Force = 0.25 * 5

Force = 1.25 N

Hence, the magnitude of the force is 1.25 Newton.