in a 1500 meter race between two speed skaters, one skater averages 45 km per hour while the other skater averages 52 km per hour.

Question

What is the difference between the two skaters finish times? 

Answer 1

We need to find the finish times for each skater, and then subtract the times.  We can find the times using this formula:

 

t = d/v

 

where:

t = time of skater

d = distance of race

v = speed of skater

 

Since we have different units, we must convert

 

(1000 m  = 1 km) 

 

 

For the skater whose speed is 45000 meter per hour  

 

t = 1500 / 45000

t =  0.033 hrs

 

For the skater whose speed is 52000 meters per hour

 

t = 1500 / 52000

t = 0.029 hrs

 

 

Now that we have their times, we just subtract them.

 

0.033 hrs - 0.029 hrs = 0.004 hrs

 

 

The differences between their times is 0.004 hours. 

 

 Lets convert hours to seconds:         1 hr = 3600 s

 

 

We will have a difference of 14.4 seconds.