Question

Power applied to a particle varies with time as

P = [3t² – 2t + 1] watts. Where t is time in seconds. Then the change in kinetic energy of particle between time t = 2s to t = 4s is –

• A. 46 J
• B. 52 J
• C. 92 J
• D. 104 J

Answer 1

Answer: (A)

46 J

Answer 2

DK = $\int _ { 2 } ^ { 4 } \mathrm { Pdt }$ = [t³ – t² + t]₂⁴ = 46J