Question

The hammer throw is a track-and-field event in which a 7.30-kg ball (the hammer) is whirled around in a circle several times and released. It then moves upward on the familiar curved path of projectile motion and eventually returns to the ground some distance away. The world record for the horizontal distance is 86.75 m, achieved in 1986 by Yuriy Sedykh. Ignore air resistance and the fact that the ball was released above the ground rather than at ground level. Furthermore, assume that the ball is whirled around a circle that has a radius of 2.28 m and that its velocity at the instant of release is directed 58.2° above the horizontal. Find the magnitude of the centripetal force acting on the ball just prior to the moment of release.

Answer 1

(1) mass of the ball m = 7.3 kg;

maximum horizontal distance achived in 1986 is x = 86.75 m;

r = 2.28 m and angle

since there is no acceleration in horizontal direction therefore horizontal distance;

x = (vcos)t ....................................(1)

use equation of motion in vertical direction;

v = u -gt;

-vsin() = vsin() - gt;

from equation (1);

find centripetal force;