A quantity that has magnitude and direction
Answer:
The correct answer is d
Explanation:
In this exercise they ask us which statement is correct, for this we plan the solution of the problem, this is a Doppler effect problem, it is the frequency change due to the relative speed between the emitter and the receiver of sound.
The expression for the Doppler effect of a moving source is
f ’= (v / (v- + v_s) f
From this expression we see that if the speed the sound source is different from zero feels a change in the frequency.
The correct answer is d
The frequency of the sound is 500
Answer:
Commutator is a ring which reverse the direction of current in AC circuit so that the coil connected to it will continuous to move in the same direction.
Explanation:
In motors there exist a coil which is rotated due to torque of magnetic field when current flow through it. Since AC current is used to run the motor so we know that AC current changes its direction after half cycle.
So here commutator plays an important role to reverse the direction of current after every half cycle so that the current goes in same direction always into the coil.
This will produce a constant direction torque on the coil so that it will rotate in same sense always.
So commutator role is to provide same direction current to the coil by reversing its direction after every half cycle
The initial velocity of the hoop is determined as 8.854 m/s.
<h3>Conservation of energy</h3>
The initial velocity of the hoop can be determined from the principle of conservation of energy.
Final potential energy = Initial kinetic energy
P.E = K.E
mgh = ¹/₂mv²
gh = ¹/₂v²
2gh = v²
√2gh = v
√(2 x 9.8 x 4) = v
8.854 m/s = v
Thus, the initial velocity of the hoop is determined as 8.854 m/s.
Learn more about initial velocity here: brainly.com/question/19365526
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