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Question
A raindrop of diameter 4 mm is about to fall on the ground. Calculate the pressure inside the raindrop. [Surface tension of water T = 0.072 N/m, atmospheric pressure = 1.013 x 105 N/m2 ]
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Solution
Given:
T = 0.072 N/m,
d = 4mm ∴ r = 2 * 10-3 m,
Po = 1.013 * 105 N/m2
To find: Pressure inside the raindrop (Pi)
Formula: Pi = Po + 2T/r
Calculation: From formula,
`P_i=1.013xx10^5+(2xx0.072)/(2xx10^(-3))`
`P_i=1.013xx10^5+0.072xx10^3`
`=1.013xx10^5+0.00072xx10^5`
`thereforeP_i=1.01372xx10^5Pa`
The pressure inside the raindrop is 1.01372 * 105 Pa.
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