An object with a mass of 7 kg is on a surface with a kinetic friction coefficient of 8 . How much force is necessary to accelerate the object horizontally at 32 m/s^2?

2 Answers
Jan 14, 2018

784 N

Explanation:

enter image source here As,the object is going on a horizontal surface,frictional force acting on it will be f = u*N or umg i.e (8*7*10) N or, 560 N

So,le't's assume we will be requiring a force of F to cause an acceleration of 32 SI units on it.

so,we can write, F-f = m*a(where, m is the mass of the object and a is its acceleration)

so, F=(560+7*32) N or, 784 N

Jan 14, 2018

The force is =772.8N

Explanation:

The mass of the object is m=7kg

The acceleration is a=32ms^-2

The coefficient of kinetic friction is

mu_k=F_r/N=8

The normal force is N=7gN

The frictional force is F_r=mu_k xx N=8*7g=56gN

The force necessary to accelerate the object is =FN

The acceleration due to gravity is g=9.8ms^-2

According to Newton's Second Law

F-F_r=ma

F=ma+F_r=((7xx32)+(56g))N=772.8N