Answer:
iv) It is 9x bigger than before
Explanation:
As the amplitudes of the new speakers add directly with the original one, taking into account the phase that they have, the composed amplitude of the sound wave is as follows:
At = A + 4A -2A = 3 A
The intensity of the wave, assuming it propagates evenly in all directions, is constant at a given distance from the source, and can be expressed as follows:
I = P/A
where P= Power of the wave source, A= Area (for a point source, is equal to the surface area of a sphere of radius r, where is r is the distance to the source along a straight line)
For a sinusoidal wave, the power is proportional to the square of the amplitude, so the intensity is proportional to the square of the amplitude also.
If the amplitude changes increasing three times, the change in intensity will be proportional to the square of the change in amplitude, i.e., it will be 9 times bigger.
So, the statement iv) is the right one.
Here's what you need to know about waves:
Wavelength = (speed) / (frequency)
Now ... The question gives you the speed and the frequency,
but they're stated in unusual ways, with complicated numbers.
Frequency: How many each second ?
The thing that's making the waves is vibrating 47 times in 26.9 seconds.
Frequency = (47) / (46.9 s) = 1.747... per second. (1.747... Hz)
Speed: How far a point on a wave travels in 1 second.
The crest of one wave travels 4.16 meters in 13.7 seconds.
Speed = (4.16 m / 13.7 sec) = 0.304... m/s
Wavelength = (speed) / (frequency)
Wavelength = (0.304 m/s) / (1.747 Hz) = 0.174 meter per second
Answer:
The answer is A
Explanation:
When a rockets thrusters push on the ground the ground pushes back on the rocket with equal force in the opposite direction. Hence the rocket takes off.
Newtons third law of motion states, for every action there is an equal and opposite reaction.
Answer:

Explanation:
From the question we are told that:
Crane Length 
Crane Mass 
Arm extension at lifting end 
Arm extension at counter weight end 
Load 
Generally the equation for Torque Balance is mathematically given by



Hey There,
Movement of earth around sun and tilt of earth on it's axis causes seasons on earth. So, the answer is B.
Hope this helps!