ON STOPPING

NZ Truth, Issue 1180, 12 July 1928, Page 17

ON STOPPING

Measured Distances With the improvement m braking gear the question frequently arises—how far should, a. car take to stop from a set speed? • - L . THERE is a reliable- formula for this which can readily be applied to any car., . ■ * The formula given is for four wheel brakes, but for two wheel braked cars the resulting, figure could be increased about 50 per cent. . ' ; .:The^ormula,isl.th^^ distance equals the. square of the speed divided by 48J. : The calculation of speed is m feet per second, ' . An. easy rule to remember .m working out : the speed m ..feet Is • that 60 rri.p.h. is equivalent to 88 feet per second,, and other, speeds, can be readily obtained by working them out m propbrtion. , \ '■ , The formula; of course, is not : - absolutely correot, and cannot be •-■ made so, therefore; it is not-neces-sary to take the exact figure. Thus 20 m.p.h. equals 29.8 feet per second, but. this can be reckoned. at 29. . Working- on this formula, a car travelling at 30 m.p.h; should be able to pull up m 44 multiplied by 44 divided by 48%, which works out at a shade under 40. . 1 It will be noticed oh working out the' formula that stopping distances increase very rapidly as the speed rises, thus at 60 m.p.h., though the car is going twice as fast, the stopping distance will be, four times as great, nearly 160. feet.