"Published in Newark, California, USA"
The block shown in the figure is acted on by its weight W = 400 lbs., a horizontal force F = 600 lbs., and the pressure P exerted by the inclined plane. The resultant R of these forces is parallel to the incline. Determine P and R. Does the block move up or down the incline?
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| Photo by Math Principles in Everyday Life |
Solution:
The first thing that we need to do is to get the x and y components of each forces and then isolate the given figure as follows
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| Photo by Math Principles in Everyday Life |
Since we don't know the direction of the resultant, let's assume that the direction is upward because the value of F is greater than the weight of a block.
The sum of x component is
The sum of y component is
Substitute the value of P to the first equation. Therefore, the value of R is
Since the value of R is positive, then the block is moving upward the incline.