In atoms, electrons surround the nucleus in specific energy levels.
Answer: Option B
<u>Explanation:
</u>
Atom, actually considered as the tiny part that is ever present in this universe. Many theories and experiments were conducted, for studying what was present inside of an atom, and many theories came into light.
And finally, Bohr-Sommerfeld Theory stated the final conclusion, that the positive charge is at the centre of the nucleus, and all the electrons revolve in their specific energy levels. If an atom wants to move to lower energy state, it should emit energy, whereas for going to higher state, it should gain energy.
Answer:
The magnitude of the average frictional force on the block is 2 N.
Explanation:
Given that.
Mass of the block, m = 2 kg
Initial velocity of the block, u = 10 m/s
Distance, d = 50 m
Finally, it stops, v = 0
Let a is the acceleration of the block. It can be calculated using third equation of motion. It can be given by :



The frictional force on the block is given by the formula as :
F = ma

|F| = 2 N
So, the magnitude of the average frictional force on the block is 2 N. Hence, this is the required solution.
Answer:
44.4°
Explanation:
Use SOH-CAH-TOA.
Sine = Opposite / Hypotenuse
Cosine = Adjacent / Hypotenuse
Tangent = Opposite / Adjacent
You're given an unknown angle, the adjacent side to that angle, and the hypotenuse. So use cosine.
Cosine = Adjacent / Hypotenuse
cos A = 10 / 14
A = cos⁻¹(5/7)
A ≈ 44.4°