An object with a mass of 15kg is moving at 9ms over a surface with a kinetic friction coefficient of 4. How much power will it take to accelerate the object at #3 m/s^2?

2 Answers
Jan 13, 2018

Frictional force acting on the object is fk= uN or, umg i.e 600 N,
So, let's assume we will be requiring a force of F to accelerate the object at 3 (msec2)
So,using equation of force we can write,
(Ffk) = ma
Or, F = (153)+600 N i.e 645 N
Now,if this force cause displacement s of the object wi th in time t,power will be (work done/time) i.e 645(st)

Jan 13, 2018

The power is =5.697kW

Explanation:

The mass of the object is m=15kg

The speed is u=9ms1

The acceleration is a=3ms2

The coefficient of kinetic friction is

μk=FrN=4

The normal force is N=15gN

The frictional force is Fr=μk×N=415g=60gN

The force necessary to accelerate the object is =FN

The acceleration due to gravity is g=9.8ms2

According to Newton's Second Law

FFr=ma

F=ma+Fr=((15×3)+(60g))N=633N

Power=Force×velocity

The power is

P=F×v=6339=5697W