Question

Find the acceleration if a train driver applies breaks and train travelling with speed 100 km/hour halts in 5 min

Answer 1

Answer:

$\frac{-5}{54} \ m/s^{2}$

Explanation:

Given:

Initial velocity = 100 km/hr

100 km/hr = $100 \times \frac{5}{18} = \frac{500}{18} = \frac{250}{9} m/s$ (u)

Final velocity = 0 m/s (As the train finally comes to rest) (v)

Time = 5 minutes

1 minute = 60 seconds

5 minutes  = 5×60 = 300 seconds (t)

To find:

Acceleration

By using the first equation of motion, which says:

V=u+at

Substituting the values, we get:

0=$\frac{250}{9}$ + a×300

0=$\frac{250}{9} +300a$

$\frac{-250}{9}=300a$

$a = \frac{-250}{9} \times \frac{1}{300}$

$a=\frac{-5}{54}$ m/s²

The acceleration is equal to $\frac{-5}{54} \ m/s^{2}$