Total time in between the dropping of the stone and hearing of the echo = 8.9 s
Time taken by the sound to reach the person = 0.9 s
Time taken by the stone to reach the bottom of the well = 8.9 - 0.9 = 8 seconds
Initial speed (u) = 0 m/s
Acceleration due to gravity (g) = 9.8 m/s^2
Time taken (t) = 8 seconds
Let the depth of the well be h.
Using the second equation of motion:
h = 313.6 m
Hence, the depth of the well is 313.6 m
Answer:
7.1 Hz
Explanation:
In a generator, the maximum induced emf is given by
where
N is the number of turns in the coil
A is the area of the coil
B is the magnetic field strength
f is the frequency
In this problem, we have
N = 200
B = 0.030 T
So we can re-arrange the equation to find the frequency of the generator:
Answer:
232.641374 mph
Explanation:
A race car has a maximum speed of 0.104km/s
Let X represent the speed in miles per hour
Therefore the speed in miles per hour can be calculated as follows
1 km/s = 2,236.936292 mph
0.104km/s = X
X = 0.104 × 2,236.936292
X = 232.641374
Hence the speed in miles per hour is 232.641374 mph
Answer:
0.6295 A
Explanation:
I=mg/BL put values in this formula.
Answer:
The distance between the earth and the star is increasing.
Explanation:
When we observe an object and its electromagnetic radiation has been displaced to blue, it means that it is getting closer to us, causing the light waves it emits to get closer together and its wavelength to decrease towards blue, this is knowm as blueshift.
On the contrary, when an object is rapidly moving away from us, the light waves or electromagnetic radiation it emits have been stretched from their normal wavelength to a longer wavelength, towards the red part of the spectrum. This is known as redshift.
This phenomenon of changes in wavelength and frequency due to movement (whether the source approaches or moves away) is described by the Doppler effect.
So for this case because the light we perceive from the star has moved to the red part of the visible spectrum, we can conclude that it is moving away from the earth, and that the distance between the star and the earth is increasing.
