British Columbia Free Tutoring And Homework Help For Physics 11

  0

0 Tutors Online Right Now

The coefficient of friction for a lawn mower moving over grass is 0.81 what force is required to accelerate the 12kg mass of the lawn mower to 1.25m/s from rest in 3.0 seconds?

4 years ago

Answered By Vishesh M

from the problem we see

initial velocity(u)= 0;

final velocity(v)=1.25m/s;

therefore from the formula v = u + at;

we find accelaration

i.e

1.25 = 0 + a(3);

a=0.4166m2/s;

we know that F = m*a;

F = 12*0.4166;

F= 5 N;

however this is the normal force.

frictional force

Ff = Fn/0.81(frictional coefficient)

FF=5/0.81= 6.17 N;

therefore you need a force of 6.17 newtons.