A train is moving at a speed of 30 meters per second. If the brakes are applied to produce a retardation of 2 meters per second squared, how long will it take for the train to stop?

B. 15 s — Using the first equation of motion, v = u + at, where final velocity v is 0, initial velocity u is 30, and acceleration a is -2. Solving for t gives 0 = 30 - 2t, so t = 15 seconds.

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$A train is moving at a speed of u = 30 m/s . If the brakes are applied to produce a retardation of a = - 2 m/s^{2}, how long will it take for the train to stop?$

A. $10 s$
B. $15 s$
C. $20 s$
D. $30 s$

Show correct answer & step-by-step solution

Correct answer: B — $15 s$

Solution

Using the first equation of motion, v = u + a t, where final velocity v = 0, initial velocity u = 30 m/s, and acceleration a = - 2 m/s^{2} . Solving for t gives $0 = 30 - 2t$, so t = 15 s .

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A train is moving at a speed of u=30 m/s. If the brakes are applied to produce a retardation of a=−2 m/s2, how long will it take for the train to stop?

Solution

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More Kinematics practice questions

$A train is moving at a speed of u = 30 m/s . If the brakes are applied to produce a retardation of a = - 2 m/s^{2}, how long will it take for the train to stop?$