Acceleration in Drag Racing
Date: 06/06/2002 at 02:21:18 From: Tim Fraser Subject: drag racing A drag race car starts from a dead stop. It travels 1/4 mile in 11.0 seconds. What is the MPH formula? Every time I try to figure out the answer I come up with an average speed. As if the speed were the same at finish as it was at start! I realize it must be some type of curve, but I never took trig or calc. Any help would be greatly appreciated. Thanks, Tim
Date: 06/06/2002 at 14:31:48 From: Doctor Ian Subject: Re: drag racing Hi Tim, Assuming that the acceleration is constant (which it probably isn't!), the equation would be distance = (1/2) * acceleration * time^2 For your example, that's 5280/4 feet = (1/2) * a * (11 sec)^2 5280/4 feet a = --------------- (1/2) 121 sec^2 = 21.8 feet/sec^2 So after 1 second, it's going about 22 feet per second. After 2 seconds, about 44 feet per second. After 11 seconds, it would be going 242 feet per second... which is about 60 miles/hour 242 feet/second * -------------- = 165 miles/hour 88 feet/second Does this help? - Doctor Ian, The Math Forum http://mathforum.org/dr.math/
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