A pencil, 15.7 cm long, is released from a vertical position with the eraser end resting on a table. The eraser does not slip. Treat the pencil like a uniform rod. What is the angular speed of the pencil just before it hits the table?
A) 17.2 rad/s
B) 7.23 rad/s
C) 3.70 rad/s
D) 24.5 rad/s
E) 16.8 rad/s

Question

Quizplus · Accepted Answer

The correct answer is A because the angular speed of the pencil just before it hits the table is 17.2 rad/s. This can be calculated using the formula:ω = √(2gh/L)where:ω is the angular speed in radians per secondg is the acceleration due to gravity (9.8 m/s^2)h is the height from which the pencil is released (15.7 cm = 0.157 m)L is the length of the pencil (15.7 cm = 0.157 m)Plugging in the values, we get:ω = √(2 * 9.8 m/s^2 * 0.157 m / 0.157 m) = 17.2 rad/s

A Pencil, 15