A Massless Meter Stick on a Horizontal Frictionless Table Top

question 31

Multiple Choice

A massless meter stick on a horizontal frictionless table top is pivoted at the 80-cm mark. A force is applied perpendicularly to the end of the stick at 0 cm, as shown. A second force (not shown) is applied perpendicularly to the stick at the 100-cm end of the stick. The forces are in the plane of the table top. If the stick does not move, the force exerted by the pivot on the stick:

• A) must be zero
• B) must be in the same direction as and have magnitude
• C) must not be directed opposite to and have magnitude
• D) must not be in the same direction as and have magnitude
• E) must be directed opposite to and have magnitude