# Math Help - Math and Physics

1. ## Math and Physics

Hi Everyone.

Straight to the problem

A skier on a slope inclined at 4.7 degrees to the horizontal pushes on ski poles and starts down the slope. The initial speed is 2.7m/s. The coefficient of kinetic friction between skis and snow is 0.11. Determine how far the skier will slide before coming to rest.

In between steps appreciated.

Thanks,
Chris

2. How much did the skier wheigh?

3. Let m be the skier’s mass, R the normal reaction of the slope on him and a his acceleration down the slope.

Resolving perpendicular to the slope surface: $R=mg\cos{4.7^\circ}$

Resolving parallel to the slope surface: $ma=mg\sin{4.7^\circ}-0.11R=mg\sin{4.7^\circ}-0.11mg\cos{4.7^\circ}$

$\therefore\ a=g\sin{4.7^\circ}-0.11g\cos{4.7^\circ}$

Note that a will be negative.

Now use $v^2=u^2+2as$ to find s.