Answer:
The slope of a position-time graph can be calculated as:

where
is the increment in the y-variable
is the increment in the x-variable
We can verify that the slope of this graph is actually equal to the velocity. In fact:
corresponds to the change in position, so it is the displacement, 
corresponds to the change in time
, so the time interval
Therefore the slope of the graph is equal to

which corresponds to the definition of velocity.
Answer:
Energy is defined as the ability to do work. Forms of energy could be kinetic energy or potential energy. Thermal or heat energy can originate from a hot object such as the sun. Energy is used to produce work. Electrical energy for lighting purposes and heating in homes and factories.
Explanation:
Energy is defined as the ability to do work and can be in various forms such as kinetic energy, potential energy, thermal, chemical, electrical energy etc.
Energy origination depends on the type of energy form in discussion. Thermal or heat energy can originate from a hot object such as the sun or an iron box, chemical energy originates from the interaction of atoms and molecules and electrical energy can be initiated by movements of electrons.
Energy is used to produce work. Different forms of energy can do different tasks such as;
Heat energy for heating water
Electrical energy for lighting purposes
Geothermal energy for producing heat and electricity
Nuclear energy for production of nuclear power
Chemical energy for facilitating chemical reactions
Taking the distance of Tarzan from the ground before and after he makes the swing:
Ho (initial height) = L(1 - cos45) = 20 (1 - 0.707) = 5.86 meters
Hf (final height) = L(1 - cos30) = 20 (1 - 0.866<span>) = 2.68 meters
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Difference in height = 5.86 - 2.68 = 3.18 meters
PE = KE
mgh = (1/2)mv^2
Solving for v:
v = sqrt (2*g*h)
v = sqrt (2*9.8*3.18)
v = 7.89 m/s
With Tarzan going that fast, it is likely that he will knock Jane off.
Answer:
C 3.6 cm, 56 degrees North of the East axis
Explanation:
The two vectors are perpendicular to each other, so we can find the magnitude of their resultant simply by using the Pythagorean theorem:

where
A = 2.0 cm is the magnitude of the first vector
B = 3.0 cm is the magnitude of the second vector
Substituting,

Now we have to find the angle. If we measure the angle as North of East, the tangent of the angle is equal to the ratio between the component along North and the component along East. Therefore, in this case:

So, 56 degrees North of East.
They are called Ions
Definition is this: atom of molecule with a net electric charge caused by the loss or gain of one or more electrons.
Hope this helps! :D