A body of mass 3 kg starts from rest with a uniform acceleration of unknown magnitude. If the body has a velocity of 30 m/s in 6 seconds, what is the power consumed in 3 seconds?
Answer & explanation
Correct answer: option 4
Newton's Equation of Motion : \(v = u + at\)
30 = a x 6
a = 5 m/s2
Force (F) = m x a
= 3 x 5 = 15 N
Also, \(v’ = u + at’\)
v’ = 5 x 3 = 15 m/s
Power consumed in 3 seconds = F x v’
= 15 N X 15 m/s
= 225 W.