# Work Done by Horse

1. Dec 10, 2008

### Shaunzio

1. A 120kg sleigh is pulled by one horse at a constant velocity for a distance of 0.75km on a level snowy surface. The coefficient of kinetic friction between the sleigh and the snow is 0.25. (a) calculate the work done by the horse. (b) calculate the work done by friction.

2. F= W * S

3. I really have no idea where to start. Thats all i really want to know. Any hints please?

2. Dec 10, 2008

### Andrew Mason

Try: Work = Force x distance where Force is the component of force in the direction of motion. Technically, it is: $W = \vec{F}\cdot\vec{S}$.

Since the sleigh is moving at constant velocity, what does that tell you about the net force on the sleigh?

What are the forces acting on the sleigh? What is the direction of the force exerted by the horse on the sleigh? What is the direction of the force that resists the pull of the horse? What determines the magnitude of this force (of resistance) which the horse is required to provide? Apply the above relation to determine the work.

AM

3. Dec 10, 2008

### Shaunzio

thanks i figured it out :)