# Basic math converting factors.

## Homework Statement

use the following conversion factors to complete the calculations that follow
4.00 flam=1.00kern 5.00 folt= 1.00kern

1.00 burb=3.00 flam 1.00 sapper= 6.00 folt

a)15.2 kern equals how many flam?

b)47.65 sapper equals how many kern?

c)0.845 flam equals how many folt?

d)one burb is equivalent to how many sapper?

## The Attempt at a Solution

a) 15.2 x 4.00= 60.8 flam

b)47.65x6.00=285.9
285.9/5=57.18

c)im not sure where to begin for this one im at work right now but i will add my own attempt when I get back home if anyone wants to give me a start that would be good.

d)for this one im pretty sure I can do it but I have to leave work right now so I will get back to this in about 45 minutes.

gneill
Mentor
You can always multiply a number by one and leave it unchanged. So set up your given equivalences as ratios that are equal to one:

$$\frac{4.00 flam}{1.00 kern} = 1$$

$$\frac{5.00 folt}{1.00 kern} = 1$$

$$\frac{1.00 burb}{3.00 flam} = 1$$

$$\frac{1.00 sapper}{6.00 folt} = 1$$

Conversions are then just a matter of successive multiplication by the appropriate ratios (or their inverses) so that the units cancel along the chain, leaving the units you want.

$$15.2 kern \times \frac{4.00 flam}{1.00 kern} = 60.8 flam$$

thanks for the help gneill I think I have c and d right using what you said heres my solutions to c and d.

c)0.845flam(1kern/4flam)= 0.21125 kern
0.21125kern(5folt/1kern)=1.01folt

d) 1burb(3flam/1burb)=3flam
3flam(1kern/4flam)=.75kern
.75kern(5folt/1kern)=3.75folt
3.75folt(1sapper/6folt)=0.6sapper

the final answer for d would be with only one significant figure right?

also is it okay if i put brackets vs an equal sign when showing my work?

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gneill
Mentor
For c, you might want to check your rounding. Should be 1.06 folt.

For d, I think you want to carry 3 significant digits. 1 burb, without a decimal point, implies an "exact" number. The sig figs of the conversion constants will apply.

ya I dont know where i got 1.01 from thanks for pointing that out. that also makes sense for d because it does show 1.00.

for a number like 190 would the significant digits be 2 or 3? and another one is 30.2100 would this be 6?

gneill
Mentor
http://www.usca.edu/chemistry/genchem/sigfig.htm" [Broken]

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thanks that gave me my answers.