Q:

In 2009 , Ussin bolt set the world record for sprinting 100 m in approximately 9 3/5 seconds.Find the average speed in meters per second

Accepted Solution

A:
Answer:He ran at an average speed of 10 5/12 meters per second.Step-by-step explanation:To find the average speed all we do is take the distance and divide it by how long it took. So in our case we do100 ÷ 9 3/5The first thing we do when solving this is take our fractions and make them into improper fractions. First, Lets make 100 into a fraction.This is actually really easy to do. Since 100 is a whole number all we need to do is add a denominator of 1. So we now have :  100/1Now for 9 3/5 Since this is a fraction with a whole number we need to do some steps.Step 1Multiply the denominator by the whole number to get the new numerator5 × 9 = 45Step 2Add the answer from Step 1 to the numerator45 + 3 = 48Step 3Put these new numbers together48/59 3/5 as an improper fraction is 48/5.Now we set up the Equation. When diving fractions we change our division signs to a multiplication sign (when multiplying fractions it's the opposite). We also have to flip the fraction were multiplying by on the right. This is called "finding the reciprocal". Once we've done this the equation looks something like this :100 x 5 =   500-----------      ---1 x 48 =      48As an improper fraction the answer is 500/48.Now we simplify the fraction.To do this, we need to find the Greatest Common Factor. This is the number were going to divide the numbers by to get the lowest possible number for both the numerator and the denominator. In our case it's 4.500 ÷ 4 = 12548 ÷ 4 = 12So now we take our new numbers (125 and 12) and combine them into a simplified improper fraction.125/12Finally, We take 125 and make it go into 12 as many times as we can. 125 can go into 12 10 times. Now we take the remaining number after we put 125 into 12 10 times 5. So we now have a remainder of which is 5. All we do is set this up in fraction form. The remainder stays as a numerator for our fraction while our new whole number (10) stays on the "outside". Our simplified fraction now is :10 5/12That's your answer. Hope this helps! Thanks and have a nice day!!