00:01
Calculate the deceleration of a snowboarder going up a 5 -degree slope, assuming the coefficient of friction for waxwood on wet snow.
00:13
Okay, so start with a free -body diagram.
00:17
So we have an incline.
00:21
This angle is 5 degrees.
00:25
And you have a snowboarder.
00:27
So it has a normal force that is perpendicular to the surface.
00:33
It has a weight that pulls it straight down.
00:38
And it has friction.
00:42
The acceleration is pulling it down.
00:50
So we're going to let positive y be perpendicular to the surface and positive x going up the incline.
01:01
Okay, so from the free body diagram we know that the net force in the x direction is the weight plus the friction and the net force in the y direction is the normal force minus the weight, and it's equal to zero because the acceleration in the y direction is equal to zero.
01:25
And we know, of course, that the weight is equal to mg.
01:31
Okay.
01:34
We also know using table 51 that the coefficient of kinetic friction is 0 .100.
01:42
So the frictional force is equal to mu k -n...