A 0.50-kg mass attached to the end of a string swings in a vertical circle (radius = 2.0 m). When the string is horizontal, the speed of the mass is 8.0 m/s. What is the magnitude of the force of the string on the mass at this position?
A) 16 N
B) 17 N
C) 21 N
D) 11 N
E) 25 N

Question

Quizplus · Accepted Answer

The force of the string on the mass is the centripetal force, which is given by:$$F_c = mv^2/r$$where:* m is the mass of the object* v is the speed of the object* r is the radius of the circleIn this case, the mass is 0.50 kg, the speed is 8.0 m/s, and the radius is 2.0 m. Plugging these values into the equation, we get:$$F_c = (0.50 kg)(8.0 m/s)^2/(2.0 m) = 16 N$$Therefore, the magnitude of the force of the string on the mass at this position is 16 N.

A 050-Kg Mass Attached to the End of a String Swings