I can run 7.4 m/s, 27% faster than my kid brother. How much head start should I give him?

Question

I can run 7.4 m/s, 27% faster than my kid brother. How much head start should I give him in order to have a tie race over 100m?

Answer 1

you run 7.4 m/s, so you run the 100 at 100/7.4 or 13.5 sec

you are 27% faster than your brother, or a factor of 1.27

his speed is 7.4/1.27 or 5.83 m/s

He will run the 100 at 100/5.83 or 17.2 sec

So he needs a head start of 17.2 - 13.5 = 3.7 sec

.

Answer 2

If your speed is 7.4 m/sec and you are 27% faster than your kid brother, then his speed is = 7.4/1.27 = 5.83 m/sec.

If both of you will simultaneously start the race, then the times involved are (using the formula Distance = Rate * Time)

For you: Time = 100/7.4 = 13.51 seconds

For your brother: Time = 100/5.83 = 17.15 seconds

In order for the two of you to cross the finish line together, you must give your brother a head start of 3.64 seconds (17.15 - 13.51).

In other words, let him run for 3.64 seconds before you take off.

Hope this helps.  

Answer 3

assuming both parties running at 100%?