Question

14. Trying to be on time for class, a girl moves at 1.4 m/s down a 52 m-long 7 points
hallway, 1.8 m/s down a much more crowded hallway that is 79 m long, and
the last 25 m to her class at 2.4 m/s. How long does it take her to reach her
class?



88S

Answer 1

Answer:

Option (2)

Explanation:

To find the time taken by the girl we will use the formula,

Time = $\frac{\text{Distance traveled}}{\text{Speed}}$

Time taken by a girl who moves down 52 m long and 1.4 m per second,

$t_1=\frac{52}{1.4}$

$t_1$ = 37.14 sec.

Time taken to move through crowded hallway,

$t_2$ = $\frac{79}{1.8}$

$t_2=43.89$ sec

Time taken to cover 25 m with speed 2.4 meter per sec,

$t_3=\frac{25}{2.4}$

$t_3=10.42$ sec

Total time taken by the girl = $t_1+t_2+t_3$

                                             = 37.14 + 43.89 + 10.42

                                             = 91.45

                                             ≈ 91 seconds

Option (2) will be the answer.