The linear expansivity of brass 0.000018k-1 Explain this statement A hole in a brass plate has diameter 20.00mm in what temperature rise must the plate be heated for the diameter to become 20.09mm?

The statement "linear expansivity of brass 0.000018k-1" means that for every 1 degree Celsius increase in temperature, the length of brass will increase by 0.000018 times its original length.

To calculate the temperature rise needed for the diameter of the hole in the brass plate to increase from 20.00mm to 20.09mm, we can use the formula:

ΔL = αLΔT

Where:
ΔL = change in length
α = linear expansivity of brass (0.000018k-1)
L = original length (20.00mm)
ΔT = change in temperature

We know that the change in length is 0.09mm (20.09mm - 20.00mm), and we want to find the change in temperature ΔT.

0.09mm = 0.000018 * 20.00mm * ΔT
0.09mm = 0.00036mm * ΔT
ΔT = 0.09mm / 0.00036mm
ΔT = 250 degrees Celsius

Therefore, the brass plate must be heated by 250 degrees Celsius for the diameter of the hole to increase from 20.00mm to 20.09mm.