A body is moving initially at 4m/s. If it's impulse after accelerating at 5m/s\(^2\) for 2s is 60Kgms\(^{-1}\). What is its mass?
A
3Kg
B
4Kg
C
6Kg
D
5Kg
Verified Correct Answer: C.
Step-by-Step Mathematical Solution
C. 6 kg
Initial velocity \( u = 4 \, \text{m/s} \), Acceleration \( a = 5 \, \text{m/s}^2 \), Time \( t = 2 \, \text{s} \)
Final velocity: \(v = u + at = 4 + 5 \times 2 = 14 \, \text{m/s}\)
Change in momentum (impulse):
\(\Delta p = m(v - u) = 60\)
Substituting for \( v \): \(m(14 - 4) = 60\)
Simplifying: \(m \times 10 = 60\)
Thus, \(m = 6 \, \text{kg}\)
Source: WAEC / JAMB / NECO Classroom Archive (Record #74552)