00:01
All right, so let's say we have a box on a 30 degree incline like this, and we're told the mass of the box is 20 kilograms, and the coefficient of friction between the box and the ramp is 0 .5, and the box starts to slide down the ramp.
00:18
So part a asks, what is the weight of the box? well, this is very simple.
00:22
It's just the mass on the acceleration due to gravity, so 196 newtons.
00:27
And then part b asked, what is the component of the weight acting? like in the direction of the plane, presumably, which they call the x direction.
00:39
So this is going to be mg times the sine of theta, where theta is the same as our incline angle.
00:46
So we'll say mg sine theta.
00:51
This is just going to be 98 newtons because it should just be half of 196...