Question

A team of dogs drags a 70.9 kg sled 1.24 kmover a horizontal surface at a constant speed.The coefficient of friction between the sledand the snow is 0.193.The acceleration of gravity is 9.8 m/s2.Find the work done by the dogs.Answer in units of kJ.

Answer 1

166.284 KJ

Explanation:

We are given that

Mass of sled =70.9 kg

Displacement of sled=1.24 km

Coefficient of friction=
`\mu=`0.193

Acceleration due to gravity=
`g=9.8m/s^2`

We have to find the work done by the dogs in units KJ

Friction force=
`\mu mg`

Friction force =f=
`0.193* 70.9* 9.8=134.1N`

Force applied by team of dogs=Friction force

F=f=134.1 N

Work done=
`F* s`

We have s=1.24 km=
`1.24* 1000=1240m`

1 km= 1000 m

Work done=
`134.1* 1240=166284 J`

1 KJ=1000J

Work done=
`(166284)/(1000)=166.284KJ`

Hence, the work done by the dogs=166.284 KJ