Answer:
Part a)

Part b)

Explanation:
As we know that the see saw bar is massless so here torque due to two masses is given as

here we will have

now we will have inertia of two masses given as

now we have

now the angular acceleration is given as

so we have

Part b)
Now if the rod is not massles then we will have total inertia given as

so we will have

now the acceleration is given as


Answer:
on the first shell (ring) there will be 2 electrons
and on the 2nd shell there will be only one electron
while in the nucleus (the middle of the diagram) there will be 4 neutrons and 3 protons
Explanation:
you can see the picture attached
A camera lens (also known as photographic lens or photographic objective) is an optical lens or assembly of lenses used in conjunction with a camera body and mechanism to make images of objects either on photographic film or on other media capable of storing an image chemically or electronically.
The thermosphere is the layer of the Earth's atmosphere directly above the mesosphere and below the exosphere. Within this layer of the atmosphere, ultraviolet radiation causes photoionization/photodissociation of molecules, creating ions in the ionosphere.