The car has gravitational potential energy (Eg)
Eg = mgh
Eg = (53kg) (9.81N/kg) (14m)
Eg = 7 279.02 J
Answer:
i = 101.4A
Explanation:
The steps to the solution can be found in the attachment below.
We have been given the frequency f = 60Hz. From this we can calculate the angular frequency of the power line.
It is assumed that sinwt = –1 in order to calculate the time varying current. Although the magnitude of the current is large, consideration should also be given to the distance between the coil and the power line. The induced emf is small considering the area of the coil which is 7.85×10-⁵m².
(35/g) = mass of 3.57kg. (9.8 for g).
<span> (35 x 0.75) = 26.25N. friction.
</span><span> (246 - 26.25) = net 219.76N. accelerating force.
</span><span> Aceleration = (f/m) = (219.76/3.57) = 61.56m/sec^2</span>
Answer: person C.
Explanation:
1) The frequency of the sound wave is perceived or detected as the pitch of the sound.
And the higher the frequency the the higher the pitch.
2) When a sound source is in motion there is an apparent change in the pitch perceived. This is the Doppler effect, which is defined as the change in the perception of the pitch in virtue of the relative motion between the listener and the emitter of the sound.
If the source of the sound is moving toward the listener, the pitch will be higher that if the sound is at rest. If the source of the sound is moving away from the listener, the pitch will be lower.
That is because the the motion of the emitter increases (or decreases, depending on whether the emitter is moving toward or away the listener) the speed of the sound waves and they arrive more frequently (or less frequently).
Then, since the sound is emitted by the motorbike and it is moving toward the person C, he will hear the highest pitch.
