Question

Question 8 5 pts On a day with atmospheric conditions at 20°C and 100 kPa, you fill up your bike tire to 550 kPa (gage). The outside temperature drops by 5°C, what does the pressure in a bike tire decrease by (closest to)? OkPa 60 kPa 100 kPa 80 kPa 20 kPa O 40 kPa

Answer 1

Pressure drop --Closest option is 20 kPa

	Inputs
1	Atmospheric Temp Ta = 20C = 293.15 K
2	Atmospheric pressure Pa = 100 kPa
3	Bike tyre preesure = 550 kPa (gage)
	hence Bike tyre pressure actual = 550+100 = P1=650 kPa
4	Temp of bike tyre air will be equal to outside atmosphere
	Hence T1 = Ta = 293.15 K
5	condition2 , atmosheric temp dropped by 5C ,
	T2 =Ta2 = 15+273.15 = 288.15 K
	To find out pressure dropped by --
	Ans
	As per Gay-Lussac's law ,
	at constant volume
	P1/T1    = P2 /T2
	Putting the values,
	650/ 293.15 =   P2 /288.15
	P2 =288.15 x 650/293.15
	P2 =638.9135
	hence drop in air pressure   = P1 - P2 = 650-638.9135
	Pressure drop = 11.08647
	Rounding off
	Pressure drop = 11.09 kPa
	the closest option is 20kPa