# Physics

A thread of mercury of length 15cm is used to trap some air in a capillary tube with uniform cross sectional area and closed at one end.With the tube vertical and the open end uppermost,the length of the trapped air column is 20cm.calculate the length of the air column when the tube is held(!)horizontally (!!)vertically with the open end underneath.atmospheric pressure =76cm of mercury

1. 👍 4
2. 👎 0
3. 👁 2,119
1. at the start air pressure in bottom of tube = 76 + 15 = 91 cm Hg
when horizontal the pressure will be 76+0 = 76 cm
P2 V2 = P1 V1 since n and R and T are the same

20 * 91/76 = 23.9

when upside down
Pair = 76 - 15 = 61 cm Hg
20 * 91/61 = 29.8

1. 👍 7
2. 👎 2
2. What if an atmospheric pressure is not given

1. 👍 0
2. 👎 0

## Similar Questions

1. ### Chemistry

The enthalpy of vaporization of mercury is 59.1 kJ/mol. The normal boiling point of mercury is 357*C. What is the vapor pressure of mercury at 25*C?

2. ### Math

A seamstress has 1/4 of a foot of thread. Then she uses 1/5 of a foot of thread to sew a hole. How much of the thread is left? A. 9/20 B. 3/20 C. 1/20 D. 1/16

3. ### physics

A u-shaped tube, open to the air on both ends,contains mercury. Wather is poured into the left arm until the water column is 10.0 cm deep. How far upward from its initial position does the mercury in the right arm rise?

4. ### Calc

Air pressure at sea level is 30 inches of mercury. At an altitude of h feet above the, air pressure, P, in inches of mercury, is given by, P =30e^(-3.23x10-5h) a)Find th equation of the tangent line at h=0. b)A rule of thumb is

1. ### Physics

At the bottom of an old mercury-in-glass thermometer is a 43-mm3 reservoir filled with mercury. When the thermometer was placed under your tongue, the warmed mercury would expand into a very narrow cylindrical channel, called a

2. ### chemistry

The freezing point of mercury is -38.8°C, is the only metal that is liquid at room temperature. What quantity of heat energy, in joules, must be released by mercury if 2.00 mL of mercury is cooled from 23.0°C to -38.8°C and

3. ### Chemistry

The freezing point of mercury is -38.8°C, is the only metal that is liquid at room temperature. What quantity of heat energy, in joules, must be released by mercury if 2.00 mL of mercury is cooled from 23.0°C to -38.8°C and

4. ### science

'the scale of a mercury-in-glass thermometer is linear. one such thermometer has a scale extending from -10 degrees Celsius to 110 degrees Celsius. the length of the scale is 240mm.' what is linear? what is meant when the question

1. ### physics

A 0.16-g spider hangs from the middle of the first thread of its future web. The thread makes an angle 7.2* with the horizontal on both sides of the spider. (A) What is the tension in the thread? (B) If the angle made by the

2. ### viscosity of blood physics

Blood takes about 1.50 s to pass through a 2.0-mm-long capillary. If the radius of the capillary is 5.00 um and the pressure drop is 2.60 kPa, calculate the viscosity of blood thanks in advance

3. ### calc check: hooke's law

A force of 27N is required to maintain a spring stretched from its natural length of 12cm to a length of 15cm. How much work is done in stretching the spring from 15 to 25cm? and this is what i did.. please check to see if i did

4. ### Chemistry

The freezing point of mercury is -38.8°C, is the only metal that is liquid at room temperature. What quantity of heat energy, in joules, must be released by mercury if 2.00 mL of mercury is cooled from 23.0°C to -38.8°C and