I need help with physics...Please help if possible!?

Question

I need to know how to add and subtract measurements. I left my book at school, and I can't remember at the top of my head.

For example: 6.20 x 10 to the 5th power(sorry, I don't know how to type exponents) mm + 7.20 x 10 to the 6th power mm(No, this isn't a homework problem I want you to do for me. I just need to know the steps on how to do it.)

If you can help in any way, please do share your knowledge. It'd be greatly appreciated!!

Answer 1

This is from Affey:

dani! u owe tracy (and me) big time! lol i asked her to get this for me to see if i can help, so u owe her :p

ok addin measurements...its just as easy as adding 1+1...what u want to do (in this case) is make everything simple...

6.2x10^5...(put it in ur calculator...ok dont lol when ur mustilpyin by ten to the power of (x10^) all ur doing is movind the decimal point...so if its to the power of a positive number, move the decimal point to the right and keep adding zero's...)

so 6.2 become 620000. (count how many places the decimal point moved) and if its a negative power, u move the decimal point to the left so 620000x10^(-5) is 6.2 (again count how many places the dots moved)

sooo put everything into simple terms like that n just add...so it becomes 620,000 + 7,200,000 = 7,820,000mm which is 7820m

hope that helped....i think ur gettin confused with the units...just ignore them n add them in at the end once u've got ur final figure...whether ur addin measurements, numbers, apples, its all the same...hope this helped!

EDIT: oh forgot to say....if u wanted to add the mdirectly, u need to make convert the powers so that they match...so in this case, u want 6.2x10^5 in a x10^6 expression...so to do that u move the decimal point on to the left (everytime u raise the power, u add an exra zero, so to balance that out, u need to move the decimal point along) so it becomes 0.62x10^6...

or if u wanted to change the 7.2x10^6 to a power of 5, slide the decimal point one to the right (cos ur multiplying by ten), so it becomes 72x10^5....so now u can add them directly, add in the number of zeros (depending on what the powers raised to) and voila....hope that didnt confuse the hell out of u cos it confused me lol

Answer 2

I'm not actually know alot from Physics, but I do know several topics. To subtract measurements, start off by multiplying 10 to the 5th power. 10 to the 5th equals to 100000, or try thinking this way 10 to the 5th is the same as multiplying 10 5 times. Now mulitiply that answer to 6.20 and equals to 620000. It's basically this way, try putting the number with the exponent in expanded form, and then mulitply it.
10 to the 6 is the same as 10 times 10 times 10 times 10 times 10 times 10.
.....
6.20 x 10 to the 5th power mm + 7.20 x 10 to the 6th power mm= 7820000 mm

Answer 3

If you are dealing with terms that have powers then you want to make all terms have the same power.

6.2x10^5
7.2x10^6

You want to either make the 5 a 6 or the 6 a 5 so you can then add them directly. lets make the 5 a 6 since standard scientific notation is N.NNNx10^P (one digit to the left of the decimal).

10^5 = (1/10)x10^6 (since the power is just the number of 10's that are multiplied together: 10^6 = 10x10x10x10x10x10 and 10^5 = 10x10x10x10x10 so (1/10)x^6 = x^5).

So put this into the first expression:
6.2x10^5 = 6.2x((1/10)x10^6) = 0.62 x10^6

You can now add them together:
6.2x10^5 + 7.2x10^6 = 0.62x10^6 + 7.2x10^6 = 7.82x10^6

Answer 4

i'm sorry, i cant help u.