Question

Hicham El Guerrouj of Morocco holds the world record in the 1500 m running race. He ran the final 400 m in a time of 51.9 s.
What was his average speed in mph over the last 400 m?

Answer 1

Answer: His average speed in mph over the last 400 m is 7.7 m/s.

Explanation:

Given: Hicham El Guerrouj of Morocco holds the world record in the 1500 m running race. He ran the final 400 m in a time of 51.9 s.

We know that , speed = $\dfrac{distance}{time}$

Here , distance = 400m and time = 51.9 s

Then, speed =  $\dfrac{400}{51.9}\approx7.7\ m/s$

Hence, his average speed in mph over the last 400 m is 7.7 m/s.

Answer 2

Answer: 17.2 MPH

Explanation:

Average speed = distance/time

400m÷ 51.9s= 7.7 m/s

Now convert m/s →MPH

m→km→mi and s→min→hr

$\frac{7.7m}{s} x$ $\frac{1 km}{1000 m} x\frac{0.6214 mi}{1 km} x\frac{60 s}{1 min} x\frac{60 mins}{1 hr} = 17.2 mph$