Tim is driving a truck to chicago He is driving at 55 miles

Tim is driving a truck to chicago. He is driving at 55 miles per hour and has to hit the brakes because of heavy traffic. His truck slows at the rate of 2 miles per hour for every 3 seconds. How fast will he be traveling 10 seconds after he hits the brakes?

Solution

Time=10 seconds
Rate of deacceleration=2 miles per 3 seconds
Original Speed=55 mph
Man hits brakes.
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After 3 seconds=>deacc = 2 mph
Speed=55-2=53 mph
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After another 3 seconds=>deacc = 2 mph
Speed=53-2=51 mph
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After another 3 seconds=>deacc = 2 mph
Speed=51-2=49 mph
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After 9 seconds,speed=49 mph
Last one second,deacc = 2/3 mph
Hence speed=
=49-2/3
=48.33 mph