if i am trying to find the diameter of an oil molecule and express my answer in scientific notation.
the info is drop of oil 0.05 cm3 from a dropper spreads out to 40 cm2
is it
vol = l x w x h
0.05cm3 = 20 x 20 xh
0.05 cm3 = 40cm2
after this im stuck as i don't know what the size of the oil molecule is
can anyone help
vol = l x w x h
0.05cm3 = 20 x 20 xh OK TO HERE.
0.05 cm3 = 40cm2 You threw away the h which is the unknown here.
after this im stuck as i don't know what the size of the oil molecule is
can anyone help
Oh, but you do know the size of the oil drop. It has a volume of 0.05 cm3 or 0.05 cc. Says so in the problem.
You have 0.05 cc = lxwxh.
The problem states that the oil drop spreads out to an area of 40 cm2. That is lxw. Now the eqution is
0.05 = 40*h
solve for h.
I think i have managed it
0.05cm3 = 40 x h
h = 0.05/ 40
h = 1.25 x 10-3cm3
is this correct please
im trying to help my daughter out on this i think i need to go back to school lol
Correct if you aren't worried about the number of significant figures. There are only two s.f. in 0.05 and two in 40 (if it is 40. and not 4 x 10^1); therefore, you are allowed only two in the answer and 1.25 has three. You must round it, if s.f. are a concern, to either 1.3 x 10^-3 or 1.2 x 10^-3 depending upon how your instructor has taught you to do it. I round to the EVEN number; therefore, I would round to 1.2 x 10^-3. A note about the 40. 40 with no decimal point after it has only one s.f., 40. has two. 4 x 10^1 has one. If the 40 has only one s.f., then 1 x 10^-3 is the answer.
To find the diameter of the oil molecule, you can use the equation for the volume of a cylinder, which is volume = πr^2h, where r is the radius and h is the height (or diameter in this case) of the cylinder.
Given that the volume of the oil drop is 0.05 cm^3, you can set up the equation as follows:
0.05 cm^3 = πr^2(h)
You also know that the area the drop spreads out to is 40 cm^2, which is equal to the base of the cylinder (πr^2). So, you can rewrite the equation as:
0.05 cm^3 = 40 cm^2 (h)
Now, you can solve for the height (diameter) of the cylinder:
h = 0.05 cm^3 / 40 cm^2
h = 0.00125 cm^3
To express this answer in scientific notation, you can move the decimal point two places to the left since it is a very small value:
h = 1.25 x 10^-3 cm^3
So, the diameter of the oil molecule would be 1.25 x 10^-3 cm.