Calculating Work Done in Pushing a Lawn Mower: A Physics Problem

[master_333]

Homework Statement

A woman pushes a lawn mower(25-kg) with a force of 400 N at an angle 45 degrees below the horizontal for a displacement of 12 meters. The coefficient of friction between the lawn and the mower is 0.1. The answer is -634 J but I get a different answer.

Homework Equations

W = F (d)

The Attempt at a Solution

W = -(coefficient of friction) (mg) (12 m)
W = - 0.1 * 25 * 9.8 * 12
W = -294J

 

[SteamKing]

Homework Statement

A woman pushes a lawn mower(25-kg) with a force of 400 N at an angle 45 degrees below the horizontal for a displacement of 12 meters. The coefficient of friction between the lawn and the mower is 0.1. The answer is -634 J but I get a different answer.

Homework Equations

W = F (d)

The Attempt at a Solution

W = -(coefficient of friction) (mg) (12 m)
W = - 0.1 * 25 * 9.8 * 12
W = -294J

You should draw a free body diagram of the lawn mower with the woman pushing it, in order to find the correct normal force.

 

[master_333]

Thank you very much that helped a lot. I realized my mistake.