Commercial divers use lift bags to aid in lifting of heavy objects underwater. A
ID: 1566240 • Letter: C
Question
Commercial divers use lift bags to aid in lifting of heavy objects underwater. Air is added to a certain bag when it is at a depth of 30.0 m in a freshwater lake. At this depth, the temperature of the water is 10.0 OC and the buoyant force on the bag is 200 N. The bag expands as it rises to a depth of 10.0 m, where the temperature is 23.0 OC. Find the buoyant force acting on the bag at the shallower depth. (When using a lift bag, the buoyant force acting on the bag determines how much the bag can lift.) ANSWER = 415 N PLEASE SHOW ALL THE STEPS
Explanation / Answer
P1 = po + rho*g*h1 = 10^5+ (1000*9.8*30) = 394000 Pa
buoyancy force Fb = rho*V1*g = 200
1000*V1*10 = 200
V1 = 0.02 m^3
T1 = 10 + 273 = 283 K
at depth 10 m
P2 = Po + rho*g*h2 = 10^5+ (1000*9.8*10) = 198000 Pa
T2 = 23 + 273 = 296 K
V2 = ?
from ideal gas equation
P1*V1/T1 = P2*V2/T2
394000*0.02/283 = 198000*V2/296
V2 = 0.0415 m^3
buyancy force Fb = rho*V2*g
Fb = 1000*0.0415*10 = 415 N