Question

3 a train is traveling from greenville, sc to atlanta, ga. as it passes through the town of flowery branch it slows from 54 km/hr to 26 km/hr. this change of speed takes 20 minutes. what is the acceleration of the train as it slows down?

Explanation:

Step1: Convert time to hours

$20 \text{ minutes} = \frac{20}{60} \text{ hr} = \frac{1}{3} \text{ hr}$

Step2: Define acceleration formula

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

Step3: Substitute values into formula

$a = \frac{26 \text{ km/hr} - 54 \text{ km/hr}}{\frac{1}{3} \text{ hr}}$

Step4: Calculate numerator first

$26 - 54 = -28 \text{ km/hr}$

Step5: Compute final acceleration

$a = \frac{-28}{\frac{1}{3}} = -28 \times 3 = -84 \text{ km/hr}^2$

Answer:

$-84 \text{ km/hr}^2$