Question

2 Hammer Throw: 10 pts Remember this: In Men's Hammer Throw at the Olympics a 16 pound ball (the ham- mer) is attached to a wire that's ap- proximately 4 ft long and whirled around a circle and let go. Olympians spin their bodies incredibly fast- during their last "wind" before release they spinning at less than a second per revolution. For the men's sport, given a few facts Figure 3: 2015 Big Ten Outdoor we're going to find out the speed of Track and Field Championship Hammer the ball, the force that the athlete Throw champion, MSU athlete Cynthia must exert in order to keep the ball Watt (Photo by Matt Mitchell). moving in a circle, and what fraction of the weight of the ball that cen- tripetal force must be. Draw a picture that shows the circle that the ball follows looking down from above. Show athlete at the center, the chain connecting the athlete to the hammer, and the hammer as a... well, a ball. Label the radius, R; the circum- ference, C; the velocity vector, F, at the position of the ball; and the force of tension vector in the chain, T: Here's what we know for Olympic Men's Hammer throw: . The ball's weight is 16 pounds.

Answer 1

Let us go to the basis first picture is drawn as per below O = Centre m = 16 Pounds = 7.251 Kg almostequalto 7.26 Kg t = 0.3 S R = 4 ft = 1.22 m Relationship of circumference of circle, C in terms of radius, R: - C = 2 pi R C = 2 * 3.14 * 1.22 = 7.66 m t = 0.3 s (given) V = C/t = 7.66/0.3 = 25.53 m/s \r\n R = 4 ft = 4 * 0.3048 = 1.22 m m = 16 pound = 16 * 0.4536 = 7.26 Kg a = V^2/R = (25.53)^2/1.22 = 534.24/m/s^2 F = ma = 7.26 * 534.24 = 3878.63 N F = centripetal force = 3878.63 N Weight of ball in Newtons = mg = 7.26 * 9.81 = 71.22 N = 3878.63/71.22 = 54.46