Reference no: EM132490498

A railroad flatcar having a mass of 18600 kg is coasting along at 21 m/s. As it passes under a bridge 10 men (having an average mass of 82 ) drop straight down onto the car. What is its speed as it emerges with its new passengers from beneath the bridge? (in m/s)

A narrow bar of uniform thickness is 11.8 m long and its mass is 16 kg. The bar is supported horizontally from a ceiling by two vertical ropes. One rope is 2.2 m from one end of the bar. The second rope is 1.6 m from the other end of the bar.

(a) What is the tension in the first rope? (In N)

(b) What is the tension in the second rope? (In N)

The low-frequency speaker of a stereo set has a surface area of 0.015 m^2 and produces 1 W of acoustical power.

a) What is the intensity at the speaker? (In W/m^2 )

b) If the speaker projects this sound power uniformly in all directions, at what distance from the speaker is the intensity equal to 0.084 W/m^2? (In m).