Two loudspeakers in a 20°C room emit 686 Hz sound waves along the x-axis.b. If the speakers are out of phase, what is the smallest distance between the speakers for which the interference of the sound waves is maximum constructive?

(I) If you tried to smuggle gold bricks by filling your backpack, whose dimensions are 54cm x 31 cm x 22 cm, what would its mass be?

(II) A bottle has a mass of 32.00 g when empty and 98.44 g when filled with water. When filled with another fluid, the mass is 89.22 g. What is the specific gravity of this other fluid?