Manometers can use liquids other than mercury to measure small pressure differences. On a day when the barometric pressure is 761.7 torr, a water manometer, connected between the atmosphere and a glass bulb containing a sample of helium gas has a height difference of 26.1 cm, The water level is higher in the arm connected to the bulb. Calculate the pressure in the bulb (in torr).

To solve this problem, we need to use the principles of hydrostatic pressure and the density of the liquids involved.

First, let's calculate the pressure exerted by the water column in the manometer. The difference in height between the two arms of the manometer is 26.1 cm.

1. Convert the height difference from cm to meters:
26.1 cm * (1 m / 100 cm) = 0.261 m

2. Calculate the pressure exerted by the water column using the formula:
Pressure = density * gravity * height

The density of water is approximately 1000 kg/m^3, and the acceleration due to gravity is approximately 9.8 m/s^2.

Pressure_water = 1000 kg/m^3 * 9.8 m/s^2 * 0.261 m = 2558 Pa

Next, let's determine the pressure inside the glass bulb containing the helium gas. We know that the pressure inside the bulb is lower than atmospheric pressure, so we need to subtract the pressure exerted by the water column from the atmospheric pressure.

The barometric pressure is given as 761.7 torr. To convert torr to Pa, we use the conversion factor:

1 torr = 133.32 Pa

Pressure_bulb = 761.7 torr * 133.32 Pa/torr - 2558 Pa = 101,326 Pa - 2558 Pa = 98,768 Pa

Finally, let's convert the pressure in Pascal to torr:

1 Pa = 1 N/m^2 = 1 N/m^2 * (1 torr / 133.32 Pa) = 1 torr / 133.32

Pressure_bulb = 98,768 Pa * (1 torr / 133.32 Pa) = 740.76 torr

Therefore, the pressure in the bulb is approximately 740.76 torr.