Success in Athletics and how to obtain it

THE RUNNING LONG-JUMP 8I given to the spring by the momentum generated in the run-up. A good turn of speed is of the greatest advantage in the running long-jump. The only point which ought to be carefully noted is that the speed must not be so great that the legs will be unable to generate the necessary impulse at the take– off board, or the muscles not be given a sufficient time to do their full work at the critical moment. The foregoing statement will be best illustrated by an assumed example: Suppose the jurp.per to weigh Io stone, or I40 pounds, the distance cleared 22 feet, and also that he approaches the take-off board three times at varying speeds of 40 yards in 5 seconds, 40 yards in 6 seconds, and 40 yards in 7 seconds ; now, these speeds represent velocities of 24, 20, and IJ"I4 feet per second respec– tively; to clear 22 feet in his jump, his impulse must generate an initial velocity of 26· 5 feet per second. This gives an increase of 2· 5 feet per second on the first speed, 6· 5 feet per second on the second, and 9·34 feet per second on the third. To find the impulse generated, the formula is : P= m (u- v). m being the mass, viz. I40 pounds, u and v, the first and second velocities respec– tively. On working this out, it will be found that the im- pulse of the force required is : (a) for 24 feet per second 350 units of impulse (b) , 20 , " , 9IO " " , (c) , IT I 4 , , , I, 3 20 , " , which clearly shows that the greater the speed acquired, the less units of impulse are required. Looking at the question in another light, the greater 6