A fine glass tube of 100 cm in length, with one end closed and one end open. When the opening is vertically upward, seal the 49 cm long air column with 20 cm mercury column, as shown in the figure. When the opening is vertically downward, what is the length of the air column closed in the tube? Let the atmospheric pressure be 76 cmHg. A 100 cm long glass tube with a uniform inner diameter. One end was sealed and the other end was opened. When the opening was vertically upward, the 49 cm long air column was sealed with 20 cm mercury. As shown in the figure, when the opening was vertically downward, how long was the sealed air column in the tube? At that time, the atmospheric pressure was 76 cmHg. A fine glass tube of 100 cm in length, with one end closed and one end open. When the opening is vertically upward, seal the 49 cm long air column with 20 cm mercury column, as shown in the figure. When the opening is vertically downward, what is the length of the closed air column in the tube? Let the atmospheric pressure be 76 cmHg.

A fine glass tube of 100 cm in length, with one end closed and one end open. When the opening is vertically upward, seal the 49 cm long air column with 20 cm mercury column, as shown in the figure. When the opening is vertically downward, what is the length of the air column closed in the tube? Let the atmospheric pressure be 76 cmHg. A 100 cm long glass tube with a uniform inner diameter. One end was sealed and the other end was opened. When the opening was vertically upward, the 49 cm long air column was sealed with 20 cm mercury. As shown in the figure, when the opening was vertically downward, how long was the sealed air column in the tube? At that time, the atmospheric pressure was 76 cmHg. A fine glass tube of 100 cm in length, with one end closed and one end open. When the opening is vertically upward, seal the 49 cm long air column with 20 cm mercury column, as shown in the figure. When the opening is vertically downward, what is the length of the closed air column in the tube? Let the atmospheric pressure be 76 cmHg.

When the glass opening is upward, the pressure produced by mercury column is 20cmHg, so the closed gas pressure is: P1=P0+20cmHg=96cmHg; when the glass opening is downward, the pressure produced by mercury column is 20cmHg, so the closed gas pressure is: P2=P0-20cmHg=56cmHg.

In a horizontally placed glass tube of uniform thickness closed at one end, there is a section of mercury that encloses an air column of 40 cm in length, which is 25 cm in length, just When the open end of the glass tube is placed vertically upward, what is the length of the air column in the tube? In a horizontally placed glass tube of uniform thickness closed at one end, there is a section of mercury that seals off an air column of 40 cm in length, which is exactly 25 cm in length When the open end of the glass tube is placed vertically upward, what is the length of the air column in the tube?

Answer:30cm
Parsing:
According to the formula: P1V1=P2V2,
When placed horizontally: P1=75cmHg, V1=sh=40s,
When placed vertically: P2=75+25=100cmHg
Therefore: V2=sh2=P1V1/P2
I.e. h2=P1sh1/P2s=75×40/100=30cm
Note: Since the units on both sides are the same and can be approximated, SI units are not used and the final calculation results will not be affected.