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3 years ago

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An engineer in a locomotive sees a car stuck on the track at a railroad crossing in front of the train . When the engineer first

sees the car, the locomotive is 110 m from the crossing and its speed is 21 m/s . If the engineer's reaction time is 0.6 s, what should be the magnitude of the minimum de celeration to avoid an accident ? Answer in units of m/s^ 2

1 answer:

8_murik_8 [283]3 years ago

4 0

Answer:

Explanation:

distance traveled during reaction time

d = vt = 21(0.6) = 12.6 m

distance remaining 110 - 12.6 = 97.4 m

Assuming we want zero speed in 97.4 m using constant acceleration.

a = (0² - 21²) / 2(97.4) = - 2.2638603...

the negative value indicates acceleration opposes initial velocity.

magnitude is

a = 2.3 m/s²

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In the image attached with this answer are shown the given options from which only one is correct.

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