Question

the velocity of a body of mass 10kg increases from 5m/s to 9 m/s when a force act on it for 2 sec

Answer 1

Initial velocity (u) = 5 m/s

Final velocity (v) = 9 m/s

Time taken (t) = 2 sec

Mass of the body = 10 kg

Let the acceleration be a.

$a = \frac{v-u}{t}$

$a = \frac{9-5}{2}$

a = 2 m/s^2

Now, Force = mass × acceleration

Force = 10 × 2

Force = 20 N

Hence, the force required to change the velocity = 20 N

Answer 2

Initial velocity (u) = 5 m/s

Final velocity (v) = 9 m/s

Time taken (t) = 2 sec

Mass of the body = 10 kg

Let the acceleration be a.

a = \frac{v-u}{t}a=tv−u​

a = \frac{9-5}{2}a=29−5​

a = 2 m/s^2

Now, Force = mass × acceleration

Force = 10 × 2

Force = 20 N

Hence, the force required to change the velocity = 20 N