Question

An object of mass 100 kg is accelerated uniformly from a velocity of 5m/s to 8m/s in 6sec. Calculate the initial and final momentum of the object. Also find the magnitude of force

Answer 1

mass (m) = 100 kg

initial velocity (u) = 5 m/s

final velocity (v) = 8 m/s

momentum = mass x velocity

then, initial momentum = 100 x 5 = 500 kg m/s

         final momentum = 100 x 8 = 800 kg m/s

acceleration (a)= change in velocity/time = (v-u)/t

here, time (t) = 6 s

then, a = (8 - 5)/6 = 0.5 m/s^2

Force = mass x acceleration = 100 x 0.5 = 50 N

Answer 2

Hey there!

Mass of object (m) = 100 kg

Initial velocity(u) = 5 m/s

Final velocity(v) = 8 m/s

Time(t) = 6 sec

Initial momentum(pi) = m * u = 100 * 5 = 500 kg m/s (←Ans)

Final momentum(pf) = m*v = 100 * 8 = 800 kg m/s (←Ans)

Now,

Force = (pf - pi) / t

          = (800 - 500) / 6

          = 300/6

          = 50 N (←Ans)