Question
Inside a sealed chamber, a wooden cube 10 cm along each side is placed on a platform scale with a precision of +- 0.01 g. Half of the air inside the chamber is then pumped out of the chamber. What will happen to the scale reading?
a.) It will decrease noticeably.
b.) It will decrease in theory, but too little to register on the scale.
c.) It will remain precisely the same.
d.) It will increase in theory, but too little to register on the scale.
e.) It will increase noticeably.
f.) It depends on... (Explain.)
Explanation / Answer
Reason: Let , intial volume of the air in the sealed chamber is : V At this position : presure in side the chamber is : P If volume is changed to half of its previous value as V/2 Acc. to boyl's law We have , P1V1 = P2V2 P V = P2 V/2 P2 = 2 P Thus, presure inside the chamber now increases to twice , Hence the weight of the scale is increases slightly as presure equal to force/ area If presure is increase , the force exrted by the air on the scale will laso be increased . thus, weight of the scale will slightly increases but it is too little to register . P V = P2 V/2 P2 = 2 P Thus, presure inside the chamber now increases to twice , Hence the weight of the scale is increases slightly as presure equal to force/ area If presure is increase , the force exrted by the air on the scale will laso be increased . thus, weight of the scale will slightly increases but it is too little to register . so, Among the given option (d) is correct