# Physics - Verification

posted by .

A skier (75 kg) goes down a 15* slope. The coefficient of kinetic friction between the skis and the snow is 0.185. The length of the slope is of 500m.

a) What is the work done by gravity?

Answer) Wmg = mgd

= 75kg(9.8N/kg)500m(sin15)
= 354 977 J

Is it cos or sin? And is Work done by both air and friction supposed to be higher than work done by gravity at the end of the slope?

• Physics - Verification -

The sine is correct function to use, but you made a mistake in the multiplication.

Work done by friction (on snow) and aerodynamic drag is negative. The skier does the work. The absolute value equals the gravity work only if the kinetic energy does not change.

• Physics - Verification -

what is the mistake? And thank you for the information!

• Physics - Verification -

and drag and friction work has to be higher at the end than gravity in order to stop the skier at the bottom, right?

• Physics - Verification -

oh and I see what you mean, it's 95 116 J, thanks again!

• Physics - Verification -

75*9.8*500*(sin15) = 9.516*10^4 J

## Similar Questions

1. ### Physics

a 61 kg skier on level snow coasts 184 m to stop from a speed on 12.0 m/s. A) use the work energy principle to find the coefficient of kinetic friction between the skis and the snow. B) suppose a 75 kg skier with twice the starting …
2. ### physics

A skier with a mass of 70 kg starts from rest and skis down an icy (frictionless) slope that has a length of 52 m at an angle of 32° with respect to the horizontal. At the bottom of the slope, the path levels out and becomes horizontal, …
3. ### Physics

A skier of mass 64 kg starts from rest at the top of an 18° slope, points her skis straight down the slope and lets gravity pull her down the slope. The slope is 65 m long. Her speed at the bottom is 15 m/s. (a) Assuming zero air …
4. ### TOm

Hello, this is the last question that I can't seem to or be able to solve: 1. Jenny (75 kg) goes on a ski trip. She goes down a slope that's inclined at 15*. The drag coefficient of Jenny is 0.300, the surface of contact with air is …
5. ### Physics

Wrote the name and subject bad in the other post, sry:: Hello, this is the last question that I can't seem to be able to solve: 1. Jenny (75 kg) goes on a ski trip. She goes down a slope that's inclined at 15*. The drag coefficient …

An 60 kg skier is sliding down a ski slope at a constant velocity. The slope makes an angle of 13° above the horizontal direction. (a) Ignoring any air resistance, what is the force of kinetic friction acting on the skier?
7. ### Physics

A skier with a mass of 56 kg starts from rest and skis down an icy (frictionless) slope that has a length of 70 m at an angle of 32° with respect to the horizontal. At the bottom of the slope, the path levels out and becomes horizontal, …
8. ### Physics

A skier with a mass of 66.6 kg starts from rest and skis down an icy (frictionless) slope that has a length of 58.4 m at an angle of 29.8° with respect to the horizontal. At the bottom of the slope, the path levels out and becomes …
9. ### physics

A skier slides down a ski slope with an acceleration 2.2 m/s^2 directed down the slope. The coefficient of kinetic friction between the skis and the slope is 0.24. What is the angle of the slope with the ground?
10. ### Physics

A 64 kg skier is on a 18 degree slope. The coefficient of kinetic friction between the skis and snow is .04. A) What is the weight of the skier?

More Similar Questions