Your brother is insisting that you’ll never hear a sound produced behind a barrier wall at the end of your yard you notice that the door within the wall is open and quickly explain to him that the sound will be able to reach you due to a. reverberation b. diffusion c. focusing d. diffraction

Answer

D.Diffraction

Explanation

Diffraction is a property that is experienced by waves when they come across a barrier when they are in motion.

The ways tends to curve behind the barrier. This is called diffraction of waves.

Now, sound is a wave and it also experience diffraction. . So the brother will be able to hear the sound due to diffraction

acceleration = (change in speed) / (time for the change)

change in speed = (20-120)= -100 m/s.

1.5 min = 90 sec

acceleration = -100/90 = -1.11 m/s^2.

we don't care about the 150kg or the 2,500 meters. they don't make any difference.

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c) up is the direction the magnetic force is acting on the charge.