Answer:
The smallest separation distance between the speakers is 0.71 m.
Explanation:
Given that,
Two speakers, one directly behind the other, are each generating a 240-Hz sound wave, f = 240 Hz
Let the speed of sound is 343 m/s in air. The speed of sound is given by the formula as :
To produce destructive interference at a listener standing in front of them,
So, the smallest separation distance between the speakers is 0.71 m. Hence, this is the required solution.
Part a
Answer: NO
We need to calculate the distance traveled once the brakes are applied. Then we would compare the distance traveled and distance of the barrier.
Using the second equation of motion:
where s is the distance traveled, u is the initial velocity, t is the time taken and a is the acceleration.
It is given that, u=86.0 km/h=23.9 m/s, t=0.75 s,
Since there is sufficient distance between position where car would stop and the barrier, the car would not hit it.
Part b
Answer: 29.6 m/s
The maximum distance that car can travel is
The acceleration is same,
The final velocity, v=0
Using the third equation of motion, we can find the maximum initial velocity for car to not hit the barrier:
Hence, the maximum speed at which car can travel and not hit the barrier is 29.6 m/s.