Question

a) There is a change in the velocity from 10 m/s to 15 m/s when a force of 300 N is applied on a body for a minute. Calculate the mass of the body. b) An object of mass 100 Kg is accelerated uniformly from a velocity of 13 m/s to 65 m/s. in 5 minutes. Calculate the initial and final momentum of the object. Also find the magnitude of the force exerted on the object.

Answer 1

Mass of object, m=100kg; initial velocity, u=5ms

−1

; final velocity, v=8ms

−1

; time, t=6s

Initial momentum =mu=100×5=500Ns

Final momentum =mv=100×8=800Ns

Force exerted on the object

F=

t

mv−mu

=

6

800−500

=

6

300

=50N