What is the inverse of 466ft^2/gal?

  • Thread starter Thread starter jactre
  • Start date Start date
  • Tags Tags
    Inverse
AI Thread Summary
The discussion revolves around converting the coverage of house paint from 466 ft²/gal to square meters per liter and an SI unit. The correct conversion yields 11.44 m²/L and 11440 m⁻¹. The main confusion arises in determining the inverse of 466 ft²/gal, where the initial calculation of 0.002 gal/ft² is questioned for its accuracy. It is suggested that the issue may relate to significant figures, as 0.002 only has one significant digit compared to the original value's three. Clarification on the correct inverse unit, potentially in liters/m², is sought.
jactre
Messages
4
Reaction score
0
The description for a certain brand of house paint claims a coverage of 466 ft2/gal. (a) Express this quantity in square meters per liter. (b) Express this quantity in an SI unit (see Appendices A and D). (c) What is the inverse of the original quantity?

I got answers for a) and b).

a) 466ft^2/gal x 1m^2/10.76ft^2 x 1 gal/231in^3 x 61.02in^3/1L = 11.44 m^2/L

b) 11.44m^2/L x 1000L/1m^3 = 11440m^-1 (L is the SI unit for volume)

c) I originally did 1/466 to get the inverse of 466ft^2/gal to get 0.002 gal/ft^2 but this is WRONG.

Any help on part C would be very much appreciated!
 
Physics news on Phys.org
I don't see how .002 gal/ft^2 is wrong. Could they mean in liters/meter^2 ?
 
phinds said:
I don't see how .002 gal/ft^2 is wrong. Could they mean in liters/meter^2 ?

I didn't understand this either. In this example, the units were given so I know gal/ft^2 is correct.

Thanks for your help!
 
It's probably considered wrong because 466 has 3 significant digits, whereas 0.002 only has one.
 
Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Back
Top