JAMB - Physics (2017 - No. 29)
A constant force of 5N acts for 5 seconds on a mass of 5kg initially at rest. Calculate the final momentum
125kgms−1
25kgms−1
15kgms−1
0kgms−1
Paliwanag
Impulse = momentum
Impulse = Force (f) × time (t)
Momentum = mass (m) × velocity (v)
∴ Ft = Final momentum - initial momentum
FT = mv - mu
Since it is initially at rest u = 0
∴ 5 × 5 = mv − m(0)
25 = mv
∴ Final momentum = 25kgms\(^{-1}\)
Impulse = Force (f) × time (t)
Momentum = mass (m) × velocity (v)
∴ Ft = Final momentum - initial momentum
FT = mv - mu
Since it is initially at rest u = 0
∴ 5 × 5 = mv − m(0)
25 = mv
∴ Final momentum = 25kgms\(^{-1}\)