Thank you for registering.

One of our academic counsellors will contact you within 1 working day.

Please check your email for login details.
MY CART (5)

Use Coupon: CART20 and get 20% off on all online Study Material

ITEM
DETAILS
MRP
DISCOUNT
FINAL PRICE
Total Price: Rs.

There are no items in this cart.
Continue Shopping

Maurice Greene once ran the 100-m dash in 9.81 s (the wind was at his back), and Khalid Khannouchi ran the marathon (26 mi, 385 yd) in 2:05:42. (a) What are their average speeds? (b) If Maurice Greene could maintain his sprint speed during a marathon, how long would it take him to finish?

Maurice Greene once ran the 100-m dash in 9.81 s (the wind was at his back), and Khalid Khannouchi ran the marathon (26 mi, 385 yd) in 2:05:42. (a) What are their average speeds?             
(b) If Maurice Greene could maintain his sprint speed during a marathon, how long would it take him to finish?

Grade:11

1 Answers

Aditi Chauhan
askIITians Faculty 396 Points
6 years ago
(a)
Substitute 100m for “distance” and 9.81s for “elapsed time” in equation average\ speed = \frac{distance}{elapsed\ time} to calculate the average speed of Maurice Greene as,
average\ speed = \frac{100 m}{93.81 s}
= 10.2 m/s

Therefore, the average speed of Maurice Greene is . 10.2 m/s.
Substitute 26 mi for “distance” and 2 g 5 min 42 sec for “elapsed time” in equationaverage\ speed = \frac{distance}{elapsed\ time} to calculate the average speed of Khalid Khannouchi as,

236-2248_khurak.JPG
Therefore, the average speed of Khalid Khannouchi is 5.54 m/s.
(b)

Substitute 26 mi for “distance” and 10.2 m/s for “average speed” in equation elapsed time = \frac{distance}{ average\ speed}, to calculate the elapsed time of Maurice Greene as:

236-1129_should.JPG
Therefore, Maurice Greene can finish the marathon in. 1.13 h.

Think You Can Provide A Better Answer ?

Provide a better Answer & Earn Cool Goodies See our forum point policy

ASK QUESTION

Get your questions answered by the expert for free