# Sled Dogs work?

1. Oct 19, 2009

### kcrox

Sled Dogs work???

A team of dogs drags a 46.5 kg sled 1.73 km over a horizontal surface at a constant speed. The coefficient of friction between the sled and the snow is 0.233. The acceleration of gravity is 9.8 m/s2 . Find the work done by the dogs. Answer in units of kJ

2. W=Fd
F=mg

3. I tried (46.5*9.8)1.73 it was wrong
(46.5*9.8)+(.233(46.5*9.8)) it was wrong

I desperately need help!

2. Oct 19, 2009

### rl.bhat

Re: Sled Dogs work???

Sled will move with uniform velocity , when the frictional force is balanced with the applied force.

3. Oct 20, 2009

### Raziel2701

Re: Sled Dogs work???

You must take in consideration that the dogs are also overcoming the frictional force of the sled. You must subtract the work done by the frictional force, which would be negative as supported by intuition.

The coefficient of kinetic friction is NOT the frictional force by the way. The frictional force is equal to the coefficient times the normal force. Also, you might want to use standard mks units throughout the calculation. Meaning that instead of km, use meters.