Answer and Explanation:
The main source of earth magnetic field is the metals and iron present in earth crust these metals are mainly found in liquid state in earth crust and we know that whenever there is spinning of these liquid metals then there will magnetic field generate, So the main source of earth magnetic field is the metals present in earth crust.
<span>An observation of the red shift of galaxies suggests that the universe is expanding. The correct option among all the options that are given in the question is the first option or option "a". I hope that this is the answer that you were looking for and it has actually come to your help.</span>
Answer:
η = 1.31
Explanation:
The formula for the refractive index of from air to some other medium is given by the following formula:

where,
η = refractive index = ?
c = speed of light in air = 3 x 10⁸ m/s
v = speed of light in ice = 2.29 x 10⁸ m/s
Therefore, using these values in the equation we get:

<u>η = 1.31</u>
Distance = speed / time
speed = 95 m/s
time = 3 s
distance = 95 / 3 m
displacement = 95/3 m or 32 m (2 s.f.)
Answer:
PE=0.29J
Explanation:
According to the description, there is a angle and in point swung upward of 70°
So,

Appling the equation of Potential Energy we have,
