Question

until a train is a safe distance from the station it must travel at 5 m/s. once the train is on open track it can speed up to 45 m/s. if it takes a train 8 seconds to reach 45 m/s, what is the acceleration of the train? (round your answer to the nearest whole number.)
○ 4 m/s²
○ 5 m/s²
○ 6 m/s²
○ 7 m/s²

Explanation:

Step1: Identify acceleration formula

Acceleration $a = \frac{v_f - v_i}{t}$ where $v_f$=final velocity, $v_i$=initial velocity, $t$=time.

Step2: Plug in values

$v_f=45\,\text{m/s}$, $v_i=5\,\text{m/s}$, $t=8\,\text{s}$. So $a=\frac{45-5}{8}=\frac{40}{8}=5\,\text{m/s}^2$.

Step3: Match with options

The calculated acceleration is $5\,\text{m/s}^2$.

Answer:

B. 5 m/s²