Converting Problems: Get Help with Formula Steps

[nutsy76]

I am having problems on conversion factors. I don't even know where to begin with my problems. I know which formulas to use I just don't know what to do after that. For ex I am working on this prob:

A Grand Prix racer completes a 500 km race in 2hr 15min. What is the average speed of the car in km per hr and meters per sec?

Like I said I know what formula to use but what are the steps to convert? I keep getting stuck on how to start.

Thanks.

 

[OlderDan]

I am having problems on conversion factors. I don't even know where to begin with my problems. I know which formulas to use I just don't know what to do after that. For ex I am working on this prob:

A Grand Prix racer completes a 500 km race in 2hr 15min. What is the average speed of the car in km per hr and meters per sec?

Like I said I know what formula to use but what are the steps to convert? I keep getting stuck on how to start.

Thanks.

All conversions should be thought of as a series of multiplications by factors equal to one. Here is an example I recently did

$$a = \frac{{45\frac{{mi}}{h}}}{{1s}} = \frac{{45mi}}{{hs}}\left( {\frac{{5280ft}}{{mi}}} \right)\left( {\frac{{12in}}{{ft}}} \right)\left( {\frac{{2.54cm}}{{in}}} \right)\left( {\frac{{1m}}{{100cm}}} \right)\left( {\frac{1 h}{{60\min }}} \right)\left( {\frac{{1\min }}{{60{\mathop{\rm s}\nolimits} }}} \right) = 20.1\frac{m}{{s^2 }}$$

Every term in parentheses is equal to one because the numerator is equal to the denominator. It is simply a matter of choosing to write the fractions in such a way that units you want to replace divide out and the units you want to convert to are left. See if you can follow this model and do your problem.

You will have to express your time either in hours or in minutes by doing a prliminary conversion of one of those and adding them together.

 

[thepatientmental]

Hello there,

It seems like you are having some trouble with converting problems and are unsure of the steps to take after identifying the formula to use. Don't worry, you are not alone! Many students struggle with conversions and it can be a bit overwhelming at first. However, with some practice and guidance, you can become confident in solving these types of problems.

Firstly, it's important to understand the concept of conversion factors. These are ratios that allow us to convert between different units of measurement. For example, 1 km = 1000 meters. This means that if we want to convert from km to meters, we can multiply the given value in km by 1000 to get the equivalent value in meters.

Now, let's apply this concept to the problem you mentioned. We are given the distance of 500 km and the time of 2 hours and 15 minutes (which can be written as 2.25 hours). To find the average speed, we use the formula: speed = distance/time. So, we have:

Speed = 500 km / 2.25 hours

To convert hours to seconds, we can use the conversion factor 1 hour = 3600 seconds. So, we multiply the given time of 2.25 hours by 3600 to get the equivalent value in seconds:

2.25 hours * 3600 seconds/hour = 8100 seconds

Now, we can plug in the converted time value into our formula:

Speed = 500 km / 8100 seconds

To convert km to meters, we use the conversion factor 1 km = 1000 meters. So, we multiply the given distance of 500 km by 1000 to get the equivalent value in meters:

500 km * 1000 meters/km = 500,000 meters

Now, we can plug in the converted distance value into our formula:

Speed = 500,000 meters / 8100 seconds

To simplify this, we can divide both the numerator and denominator by 100 to get the speed in meters per second:

Speed = 5000 meters / 81 seconds = 61.73 meters/second

To convert this to kilometers per hour, we can use the conversion factor 1 meter/second = 3.6 kilometers/hour. So, we multiply the speed in meters/second by 3.6 to get the equivalent value in kilometers/hour:

61.73 meters/second