If the distance between two charges is halved, the electrical force between them increases by a factor 4.
In fact, the magnitude of the electric force between two charges is given by:

where
k is the Coulomb's constant
q1 and q2 are the two charges
r is the separation between the two charges
We see that the magnitude of the force F is inversely proportional to the square of the distance r. Therefore, if the radius is halved:

the magnitude of the force changes as follows:

so, the force increases by a factor 4.
B-things that can attract iron.
Car A take a time of 2.55hr and car B take a time of 2.14 hr
We know that distance divide by time is speed
here it is given that car A to reach a gas station a distance 189 km from the school traveling at a speed of 74 km/hr
so speed=distance/time
s=d/t
t=d/s
=189/74
=2.55hr
In case of car B it is given that The distance from the is 199.8km, car b is traveling at a speed of 93 km/hr
s=d/t
t=d/s
=199.8/93
=2.14hr
so from the above given data and the formula we solved and found out the time taken by car A is 2.55h and car B is 2.14h
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Answer:
Explanation:
a ) AM radio band (540–1600 kHz)
frequency = 540 kHz = 540 x 10³ Hz
wave length = velocity of light / frequency
= 3 x 10⁸ / 540 x 10³
= 555.55 m
frequency = 1600 kHz = 1600 x 10³ Hz
wave length = velocity of light / frequency
= 3 x 10⁸ / 1600 x 10³
= 187.5 m
maximum wavelength = 555.55 m
minimum wavelength = 187.5 m
b )
AM radio band (88 - 108 MHz)
frequency = 88 MHz = 88 x 10⁶ Hz
wave length = velocity of light / frequency
= 3 x 10⁸ / 88 x 10⁶
= 3.41 m
frequency = 108 MHz = 108 x 10⁶ Hz
wave length = velocity of light / frequency
= 3 x 10⁸ / 108 x 10⁶
= 2.78 m
maximum wavelength = 3.41 m
minimum wavelength = 2.78 m
I'm not accurately sure if you're asking for why the bulb of a thermometer is in a cylindrical shape. So let me continue. The shape of the which is thin and cylindrical in the shape is the increase of the effect of mercury in the tube to rise and fall depending on the contact temperature.