Answer:
t = 67.04 s
Step-by-step explanation:
given,
time taken by Lace on the side walk = 2 min 47 s
= 167 s
time taken by the Lace while walking = 112 s.
now, time taken by the Lace when he is walking on the side walk = ?
Assume the distance be equal to 'd'
speed of Lace on side walk
we know, distance = speed x time
![v_(sidewalk)=(d)/(167)](https://img.qammunity.org/2021/formulas/physics/high-school/5j4fccvq1jyo1cxbxqp5woe8dkqvsujzdn.png)
speed of the lace while walking
![v_(walking)=(d)/(112)](https://img.qammunity.org/2021/formulas/physics/high-school/lxb05dig9hp70sx1gvcn973s12bpxhacqj.png)
time taken by Lace to cover the distance by walking on the side walk
![t = (distance)/(v_(sidewalk)+v_(walking))](https://img.qammunity.org/2021/formulas/physics/high-school/gbbv6gz0kql8qvlh4l7fjiynzcd5bhgpwj.png)
![t = (d)/((d)/(167)+(d)/(112))](https://img.qammunity.org/2021/formulas/physics/high-school/c1r7cusb3qymp3swzchox286rcoddr96e9.png)
![t = (167* 112)/(167+112)](https://img.qammunity.org/2021/formulas/physics/high-school/fagiixnlv6wof9sxu8exbaoravoygp1leg.png)
t = 67.04 s
time taken by the Lace walking on the side walk is equal to 67.04 s