Physics HELP!!!?

Question

Hello guys! I'm a 4th year student and were studying bout conversion of units, and I don't get it!!!
heres one example on the book, I don't know how'd they got the answer:

75m² x 10²cm x 10²cm
  = 75x10 4(4 is an exponent) cm²
1m 1m
=7.5 x 10 5(5 is an exponent)cm²

now tell me.. how did that happen, do i need to divide that, or this or multiply that.... ? what do i need to do to get that answer, how did that answer happened. Best answer gets 10 points!!
Thanks guys

Answer 1

OK you need to get the units to match.
m=100cm so 1m^2 = 100cm x 100cm=10000cm^2
10^2cm=100cm=1m
So
75m2 =(75m^2 x 10000cm^2)/m^2
=750000cm^2=75x10^4cm^2

So in the equation
(75m^2 x 10^2cm x 10^2cm)/(1m1m)=75x10^4cm^2
Substitute in
(75x10^4cm^2 x 1m x 1m)/(1m x 1m)=75x10^4cm^

now simplify the fraction since you have 1m x 1m on the top and the bottom of the fraction they will cancel out leaving you with
75x10^4cm^2=75x10^4cm^2

now since you are using exponents of 10
75=7.5x10^1

so

(7.5x10^1)x10^4cm^2
we know that when multiplying like numbers the exponent is added so 10^1 x 10^4= 10^5

therefore
75x10^4cm^2=7.5x10^5cm^2

Answer 2

Hi Cool C. What is happening in this sequence is the numbers are being converted to scientific notation (exponents).

10^2 = 10 x 10 = 100 (note: I am using ^ to indicate that the next number, 2, is an exponent)

10^2 x 10^2 = 100 x 100 = 10,000 which equals 10^4 (when you multiply numbers with exponents you just 'add' the exponents, so 10^2 x 10^2 = 10^(2+2) = 10^4).

75 = 7.5 x 10^1

So ...

75 x 10^2 x 10^2 = 7.5 x 10^1 x 10^2 x 10^2

Adding the exponents gives us:

7.5 x 10^5

Hope this helps you. Best wishes and good luck.

Answer 3

can you please write this out better and then i'll happily explain


i'll check back