They don't seem interchangeable. Here's a specific problem I just did (and got right). Is the way I used trig towards the top correct (I reasoned that the component passes though the adjacent and hypotenuse so it must be cos)?
Not a direct problem but this is a homework related question so I'm posting it here. When getting components with respect to gravity it is often intuitive, this isn't always the case. None of my classes thus far have talked about why when to use sin or cos, they just do. I'm wondering how I can...
I think I might have an answer. Imagine a box on top of another, there is a large static friction coefficient between the two boxes and none on the floor. When the bottom box is moved the static friction will cause the box to move, thus doing work. Is this correct?
Homework Statement
Static friction can never do work on an object.
a. True
b. False
Homework Equations
The answer is False, indicating that static friction can do work.
The Attempt at a Solution
W=fd, when d=0 w=0 regardless of the force.
How does this work? Or is the online...