Your body is pushing down on a chair because it is being attracted by gravity, the reason that your body is not moving down because there is a normal force acting on your body; together the net force of weight (m*g) and normal force is equal to zero
Answer:
Probably the more correct version of the story is that Newton, upon observing an apple fall from a tree, began to think along the following lines: The apple is accelerated, since its velocity changes from zero as it is hanging on the tree and moves toward the ground. Thus, by Newton's 2nd Law there must be a force that acts on the apple to cause this acceleration. Let's call this force "gravity", and the associated acceleration the "acceleration due to gravity". Then imagine the apple tree is twice as high. Again, we expect the apple to be accelerated toward the ground, so this suggests that this force that we call gravity reaches to the top of the tallest apple tree.
The law of conservation of energy is:
-- Energy can't be created or destroyed.
-- Energy can't just appear out of nowhere. If you suddenly have
more energy, then the 'extra' energy had to come from somewhere.
-- Energy can't just disappear. If you suddenly have less energy,
then the 'missing' energy had to go somewhere.
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There are also conservation laws for mass and electric charge.
They say exactly the same thing. Just write 'mass' or 'charge'
in the sentences up above, in place of the word 'energy'.
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And now I can tell you that the conservation laws for energy and mass
are actually one single law ... the conservation of mass/energy. That's
because we discovered about 100 years ago that mass can convert
into energy, and energy can convert into mass, and it's the total of BOTH
of them that gets conserved (can't be created or destroyed).
How much mass makes how much energy ?
The answer is E = m c² .
Ultravoilent rays is an type of an electromegnetic wave with wavelength 10nm .Ultraviolet wave is used by doctors in order to keep the wounds away from bacteria.
<h3>What is ultravoilent wave ?</h3>
Ultravoilent rays is an type of an electromegnetic wave with wavelength 10nm. Ultravoilent wave is directly comes frim the sun. It is classified into the UV(A) , UV(B),UV(B).
Ultravoilet rays also effects the human eyes that s why sun glasses are used. The experiments here are compared and quantified to the effectiveness of the sunscreens with various strengths.
To learn more about the ultravoilent wave refr to the link;
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Weight of an object is given by the formula W = m x g , where
m : mass of the object
g : gravitational acceleration
It is <u>independent of the horizontal </u><u>acceleration</u>.
<h3>What do we mean by weight of an object?</h3>
Weight is a gauge of how strongly gravity is<u> pulling something down.</u> It is dependent on the object's mass, or how much matter it consists of. It also depends on the <u>object's uniformly distributed</u> downward acceleration caused by gravity.
This equation can be used to express weight:
W = m x g
<h3>What is the difference between weight and mass of an object?</h3>
In everyday speech, the phrases "mass" and "weight" are frequently used interchangeably; nevertheless, the two concepts don't have the same meaning. In contrast to weight, which is a <u>measurement of</u> how the <u>force</u> of gravity works upon a mass, mass is the <u>amount of substance</u> in a material.
To learn more about gravity and acceleration :
brainly.com/question/13860566
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