Answer:
m = 0.51[kg]
Explanation:
Potential energy is defined as the product of mass by gravity by height.
where:
Epot = potential energy = 15 [J]
m = mass [kg]
g = gravity acceleration = 9.8 [m/s²]
h = elevation = 3 [m]
Now replacing:
![E_{pot}=m*g*h\\15=m*9.8*3\\m = 0.51[kg]](https://tex.z-dn.net/?f=E_%7Bpot%7D%3Dm%2Ag%2Ah%5C%5C15%3Dm%2A9.8%2A3%5C%5Cm%20%3D%200.51%5Bkg%5D)
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
<span>Both electric and magnetic fields exert body forces, meaning they act from a distance. The like charges and poles in both repel; positive charge repels positive and the north pole repels the north pole. For both, the opposite poles/charges attract. Finally, only magnetic fields have poles, and there are two poles, namely the south and north, so they are dipolar.
The diagram that represents all of this information correctly is the third.</span>
Electric field lines always begin at positive charges (or at infinity) and end at negative charges (or at infinity).
One could also say that the lines we use to represent an electric field indicate the direction in which a positive test charge would initially move when released from rest.
