Question

(i) Define momentum. State its SI unit.
(ii) An object of mass 50 kg is accelerated uniformly from a velocity of 4 m/s to 8 m/s in 8 s.
Calculate the initial and final momentum of the object. Also find the magnitude of the force
exerted on the object.

Answer 1

Hey friend,

Momentum in simple terms can be defined as mass in motion. 
If  the definition is for your assignment or work:
It is the product of mass and velocity which refers to the quantity of motion that an object has.
Momentum = mass * velocity

SI unit : kg ms^-1
Initial momentum: 200 kg ms^-1
Final momentum: 400 kg ms^-1

Hope this helps!

Answer 2

(i)Momentum can be defined as the product of the object's mass and it's velocity.
it's SI unit is kilogram meter per second

(ii) m = 50 kg
u = 4m/s
v = 8m/s
t = 8 sec

up =mu
=50×4
=200kg m/s

vp =mv
=50×8
400kg m/s

We know that,
F=(mv-mu)/t
=(400-200)/8
=200/8
=25N

Hope this helps you.Thank you.