If a #2 kg# object is constantly accelerated from #0m/s# to #15 m/s# over # 12s#, how much power musy be applied at #t= 3 #?

1 Answer
Apr 9, 2018

The power is #=9.375W#

Explanation:

Mass of the object is #m=2kg#

To calculate the acceleration, apply the equation of motion

#v=u+at#

The acceleration is

#a=(v-u)/t=(15-0)/12=1.25ms^-2#

According to Newton's Second Law of Motion

#F=ma#

The force is

#F=2*1.25=2.5N#

The speed at #t=3s# is

#v=0+1.25*3=3.75ms^-1#

The power is

#P=Fv=2.5*3.75=9.375W#