00:01
For part a, we can find the kinetic force of friction.
00:03
This would be equalling the coefficient of kinetic friction times the normal force, or in this case the mass times the acceleration due to gravity, where the normal force is equaling the weight.
00:13
So we can say that then this would be equaling 0 .30, multiplied by 12 .0 kilograms, multiplied by 9 .80 meters per second squared.
00:27
And we find that the kinetic force of friction is equaling 35 .2.
00:31
8 newtons.
00:34
So this would be, we can round this, say 35 .3 newtons.
00:40
This would be the kinetic force of friction for part a.
00:44
For part b then, if we wanted to find the acceleration, we know that the acceleration of the block, rather, the sum of the forces in the x direction is equaling the mass times the acceleration in the x direction.
00:57
And in this case, we only have the kinetic force of friction, or rather better yet the negative kinetic force of friction.
01:04
And so this is going to be equal to negative mu kmg.
01:08
The masses are going to cancel out, and the acceleration in the x direction would be equal to negative mu subkg.
01:15
So this is equaling negative 0 .30 multiplied by 9 .8 meters per second squared...