be in the direction. And since the sled is not moving in the direction, the y-component of the
net force must be zero. Because the y-component of Larry’s force is zero, this implies:
where is the y-component of M and is the y-component of C. We also know:
If we substitute these two equations for and into the equation , we have:
What is the acceleration of the sled?
According to Newton’s Second Law, the acceleration of the sled is a = F/m. We know the sled has
a mass of 10 kg, so we just need to calculate the magnitude of the net force in the -direction.
Now that we have calculated the magnitude of the net force acting on the sled, a simple
calculation can give us the sled’s acceleration:
We have been told that the sled is moving in the direction, so the acceleration is also in the
direction.
This example problem illustrates the importance of vector components. For the SAT II, you will
need to break vectors into components on any problem that deals with vectors that are not all
parallel or perpendicular. As with this example, however, the SAT II will always provide you with
the necessary trigonometric values.
EXAMPLE 2