A team of dogs drags a 73.1 kg sled 3.08 km over a horizontal surface at a constant speed. The coefficient of friction between the sled and the snow is 0.235. Find the work done by the dogs and the energy lost due to friction.
2007-03-05 14:11:36 · 1 answers · asked by guardchic05 2 in Science & Mathematics ➔ Physics
The work done by the force is :
W = initial energy minus final energy.
This is known by the energy - work theorem :
The dogs drag the sled at a constant speed, so the force of friction will be :
f = (Normal force)*coefficient of friction
f = 73.1g*0.235
g = gravity = 9.8 m/s^2
f = 168.3 newtons >>> force of friction
Work done by the dogs is the same work done by the force of friction because they are moving at a constant speed :
168.3*3.08*1000 = 518364 Joules
The energy lost due to friction is : initial energy - final energy
So then, using the energy work theorem, the energy lost will be the work done by friction but with minus sign :
Energy lost = -518364 Joules
Hope that might help you
2007-03-05 14:56:43 · answer #1 · answered by anakin_louix 6 · 0⤊ 0⤋