Question

PRINTER VERSION BACk NE Chapter 02, Problem 08 GO An 18-year-old runner can complete a 10.0-km course with an average speed of 4.52 m/s. A 50-year-old runner can cover the same distance with an average speed of 3.86 m/s. How much later (in seconds) should the younger runner start in order to finish the course at the same time as the older runner? Number Units the tolerance is +/-5% GO TUTORIAL LINK TO TEXT LINK TO TEXT

Answer 1

Problem-8

Given is:

Distance of the course = 10 km or  

speed of the old runner  

speed of the young runner  

Now,

the time taken by old runner to complete the course is

by plugging all the values we get

which gives us

Similarly time taken by the young boy is

Thus

the time difference is

Hence,

the younger boy should start the race 378 seconds later than the old runner to finish the line at the same time