Success in Athletics and how to obtain it

THE STANDING LONG-JUMP 73 Expressed in another way, were he able to do any better than he had previously been doing, and if he directed his efforts to jumping at the correct angle of 45°, he would attain a greater range than he had been doing in the first instance. In short, it will readily be seen from the foregoing remarks that, no matter how good the effort, if directed at the wrong angle, the best result cannot be attained. The following few figures may serve as an illustra– tion and prove of some interest. Dealing w~th diagram 12, and assuming– . A man of 12 stone (168 pounds) and a jump of 10 feet. He leaves the take-off board with a velocity of 17·8 feet per second. Jumping at the correct angle of 45 °, he attains a height of 2ft. 6 in. half way. His initial horizontal and vertical velocities are both 12·6 feet per second. The impressed force exerted is 93"45 pounds. The kinetic energy is 83 1"6 foot-pounds. ("Force is that which changes or tends to change the state of.. rest or uniform motion of a body.") (" Kinetic energy is the energy due to the motion of a body, and is increased by the amount of work that the body can perform against the impressed force.s before its velocity is destroyed.") Once the athlete has accustomed himself to jumping well up into the air as the first thing necessary to enable him to get a good long-jump, he will find the rest of the movements come to him fairly easily in time and with practice. Consider two men of exactly equal physique and strength, one of whom thrusts away .from the board and jumps straight forward, passing fairly close to