During a test by the editors of an auto magazine, the stopping distance s (in metres) of the MacPherson X-2 racing car conformed to the rule s=f(t)=40t−5t2(t≥0) where t was the time (in seconds) after the brakes were applied. a. Find an expression for the car's velocity v at any time t. b. What was the car's velocity when the brakes were first applied? c. What was the car's stopping distance for that particular test? Hint: The stopping time is found by setting v=0.

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During a test by the editors of an auto magazine, the stopping distance s (in metres) of the MacPherson X-2 racing car conformed to the rule s=f(t)=40t−5t2(t≥0) where t was the time (in seconds) after the brakes were applied. a. Find an expression for the car&#039;s velocity v at any time t. b. What was the car&#039;s velocity when the brakes were first applied? c. What was the car&#039;s stopping distance for that particular test? Hint: The stopping time is found by setting v=0.

StrycharzT · Accepted Answer

a)The velocity is the displacement over time so we divide s by t: v(t)=st v(t)=40t−5t2t v(t)=40−5t b)The brakes were first applied at t=0 so using v(t):v(0)=40−5(0) v(0)=40→40ms c)Setting v=0, we have 0=40−5t 5t=40 t=8→8 seconds

During a test by the editors of an auto magazine, the stopping distance s (in metres) of the MacPherson X-2 racing car conformed to the rule s=f(t)=40

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