- #1
Hamal_Arietis
- 156
- 15
Homework Statement
As show in the figure below, balloon A (containing gas of density ##ρ_A##) and balloon B (containing gas of density ##ρ_B##) are each suspended by string from the ceiling of a train at rest. Balloon C (containing gas of density ##ρ_C## is attached to the train floor by string, and floats above the floor. The density of the air is ##ρ_o##, where ##ρ_C<ρ_o<ρ_B<ρ_A##. The balloon's mass, the string's mass at the movement of air inside the train are negligible.
The train begins moving with uniform accleration in a horzizontal direction (to the right in the figure). A, B, S come to rest with respect to the train and form, respectively, angles ##\theta_A;\theta_B;\theta_C## with the vertical. Choose the best represents the condition inside the train at this time.
Homework Equations
F=-ma
The Attempt at a Solution
$$tan \theta_A=\frac{g\rho_A V-g\rho_oV}{V\rho_Aa}$$
$$tan \theta_B=\frac{g\rho_B V-g\rho_oV}{V\rho_Ba}$$
Because ##\dfrac{\rho_A-\rho_o}{\rho _A}>\dfrac{\rho_B-\rho_o}{\rho _B}##
and I choose 1. But the answer is 4. Where is my wrong?
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