A mass of 100 g is attached to one end of a massless rod, 10 cm in length, which is pivoted about the opposite end. The rod is held vertical, with the mass at the top, and released. The rod swings. What is the speed of the mass at the instant that the rod is horizontal?

Question

Quizplus · Accepted Answer

The potential energy at the top is converted to kinetic energy at the horizontal position. Using conservation of energy: mgh = 0.5mv^2. Solving for v gives v = sqrt(2gh) = sqrt(2*9.8*0.1) = 1.4 m/s.

A Mass of 100 G Is Attached to One End