A coffee mug of weight W is at rest on a table. What set of forces, if any, are acting on the mug?
A. a downward force of magnitude W
B. both a downward force and an upward force, each of magnitude W
C. an upward force of magnitude W
D. no forces
The correct answer is D. no forces.
According to Newton's first law of motion, an object will remain at rest or continue to move in a straight line at a constant velocity unless acted upon by an external force. Since the coffee mug is at rest on the table, there is no need for any forces to be acting on it. The only force that could be acting on the mug would be the normal force from the table, but since the mug is at rest, the normal force is equal in magnitude and opposite in direction to the weight of the mug, resulting in a net force of zero. Thus, no forces are acting on the mug.
The correct answer is D. no forces.
When an object is at rest on a table, the forces acting on it are balanced. This means that the forces are equal and opposite, resulting in a net force of zero. Since the coffee mug is not moving, there is no need for any forces to act upon it. Therefore, there are no forces acting on the mug.