Question

A force in the negative x-direction is applied for 27 ms to a 0.4 kg mass initially moving at +14 m/s in the x-direction. The force varies in magnitude and delivers an impulse with a magnitude of 32.4 N-s. What is the mass's velocity in the x-direction? Give the vector component in m/s.

Answer 1

It is given that,

Mass of the object, m = 0.5 kg

A force is applied for 27 ms.

Initial speed of the object, u = +14 m/s

Impulse of the force, J = 32.4 N-s (in negative direction)

Let v is the velocity of mass in x direction. We know that the impulse of an object is equal to the change in momentum. It is given by :

`J=m(v-u)`

`-32.4=0.4* (v-14)`

v = -67 m/s

So, the velocity of the mass is 67 m/s and it is in negative x direction.