Answer:
A free body diagram is used to calculate static and dynamic forces acting on an object. In other words, a free body diagram is the starting point to develop a mathematical model to find and calculate various forces acting on a body.
Explanation:
Answer:

Explanation:
Using the expression for the photoelectric effect as:

Also, 

Applying the equation as:

Where,
h is Plank's constant having value 
c is the speed of light having value 
is the wavelength of the light being bombarded
Given, 
is the binding energy or threshold energy
is the kinetic energy of the electron emitted. = 
Thus, applying values as:





Answer:
- contains oxygen
- provides warmth
- blocks harmful energy from the Sun
Explanation:
The atmosphere is crucial when it comes to providing living conditions on Earth. The gases in the atmosphere manage to balance the things just about right, so that the life can thrive. The atmosphere has oxygen, the gas that is used by pretty much every organism to be able to function. With its greenhouse gases, the atmosphere manages to trap the heat inside, thus providing warmth to the Earth. The numerous layers of the atmosphere manage to block in big portion the harmful energy from the Sun, with a special accent on the ozone layer, a layer that manages to stop most of the UV radiation.
Answer:
Single displacement reaction
Explanation:
2AI + 6HCI —> 2AlCl3 + 3H2
From the above reaction, we see clearly that Al displaces H from HCl. This is clearly a single displacement reaction.