Homework Help: Physics

Posted by Mandeep on Wednesday, August 22, 2012 at 10:11pm.

A man pulls a 25kg sled a distance of 80 meters across a flat, snowy surface. He holds the handle of the sled at an angle of 30degrees with the ground. How much work does he do on the sled against the force of friction?(Assume the coefficient of sliding friction between the sled and the snow to be .1, and cos30=.87).

Physics - Henry, Friday, August 24, 2012 at 8:24pm
Ws = m*g = 25kg *9.8N/kg = 245 N. = Wt of sled.

Fs = 245N @ 0o. = Force of sled
Fp = 245*sin(0) = 0 = Force parallel to
surface.
Fv = 245*cos(0) = 245 N. = Force perpendicular to surface.

Fn = Fap*cos30-Fp-0.1(Fv-Fap*sin30) = ma
0.87Fap-0-0.1(245-0.5Fap) = 25*0 = 0
0.87Fap - 24.5 + 0.05Fap = 0
0.92Fap - 24.5 = 0
0.92Fap = 24.5
Fap = 24.5 / 0.92 = 26.6 N. = Force applied.

Work = Fap*cos30 * d
Work = 26.6*cos30 * 80 = 1851.4 Joules.

Answer this Question

Related Questions

Physics - A man pulls a 25kg sled a distance of 80 meters across a flat, snowy ...
Physics - A man pulls a 25kg sled a distance of 80 meters across a flat, snowy ...
physics - You pull your little sister across a flat snowy field on a sled. Your ...
physics - You pull your little sister across a flat snowy field on a sled. Your ...
physics - You pull your little sister across a flat snowy field on a sled. Your ...
Physics - A boy pulls a sled with a force of 40N on a rope 2.5 meters long. The ...
Physics - A boy pulls a sled with a force of 40 N on a rope 2.5 meters long. The...
physics - Wayne pulls a 305 N sled along a snowy path using a rope that makes a ...
physics - A boy pulls a sled of mass 5.0 kg with a rope that makes an 60.0° ...
physics - Diego pulls a 4.5 kg sled across level snow with a force, F, of 200 N ...

For Further Reading

First Name:
School Subject:
Answer: