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
Correct Answer: Option B
Explanation
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})
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