Question
The discus throw is a track and field event in which an athlete throws a heavy disc, called a discus, in an attempt to mark a farther distance than their competitors. To throw a discus, the thrower holds it with a fully outstretched arm. Starting from rest, he begins to turn with a constant angular acceleration. The diameter of the circle in which the discus moves is about 1.8 m. If a thrower takes 1.0 s to complete one revolution, starting from rest, what will the speed, v, of the discus be at release?
Explanation / Answer
from the given data,
radius of the cirlce, r = d/2
= 1.8/2
= 0.9 m
angular speed of the disk in his hand, w = angular displacement/time taken
= 2*pi/1
= 6.28 rad/s
the speed at whihc the disk is realesed,
v = r*w
= 0.9*6.28
= 5.65 m/s