I can go ahead and solve for frictional force.
[NOISE] So I'm trying to solve for my frictional force.
I can go ahead and do that by using the equation.
[NOISE] Frictional force equals coefficient of kinetic friction,
which is provided to us.
Multiplied by the normal force, the force being exerted by the surface.
This gives me [NOISE] 0.2 multiplied by
the answer we had just received, 22.6.
[NOISE] My frictional force turns
out to be 4.52 newtons.
And of course, I will include the direction over here.
This force is pointed towards the left.
This is for my pre-body diagram, comes in handy because I can always look back and
see which direction this vec, vector was pointed in.
The next part of this question asks us to solve for the acceleration.
Again, I can look at my pre-body diagram.
And I know that this object is moving horizontally, so
I'm going to look at [NOISE] the sum of my horizontal forces, set them equal to ma.
All the forces that I have acting horizontally,
this includes my negative frictional force.
Remember, because it was towards the left.
My positive [NOISE] force applied cosine of theta.
Recall, I'm using the horizontal component of that applied force.
[NOISE] Set all of this equal to mass times acceleration.
Frictional force negative 4.52 [NOISE] plus 30.
[NOISE] Cosine of 20 degrees.
[NOISE] Set this equal to the mass, which is 5 kilogram times the acceleration.
From here, when I solve for the acceleration,
[NOISE] I end up with 1.54 meters per second squared.
Now, I haven't put a direction down here yet, but let's talk about how I would
figure out whether this object's accelerating towards the left,
towards the right.
I can compare my two horizontal forces.