A constant force of 5N acts for 5 seconds on a mass of 5kg initially at rest. Calculate the final momentum
A
125kgms−1
B
25kgms−1
C
15kgms−1
D
0kgms−1
Verified Correct Answer: B.
Physical Principles & Numerical Solution
Impulse = momentum
Impulse = Force (f) \times time (t)
Momentum = mass (m) \times velocity (v)
∴ Ft = Final momentum - initial momentum
FT = mv - mu
Since it is initially at rest u = 0
∴ 5 \times 5 = mv − m(0)
25 = mv
∴ Final momentum = 25kgms\(^{-1}\)
Source: Myschool Past Questions Archive (Record #46409)