Answer:
"A pendulum swinging back and forth" is an example of harmonic motion
X = Xo cos ω t
Explains the back and forth motion of the pendulum
Thank you for your question, what you say is true, the gravitational force exerted by the Earth on the Moon has to be equal to the centripetal force.
An interesting application of this principle is that it allows you to determine a relation between the period of an orbit and its size. Let us assume for simplicity the Moon's orbit as circular (it is not, but this is a good approximation for our purposes).
The gravitational acceleration that the Moon experience due to the gravitational attraction from the Earth is given by:
ag=G(MEarth+MMoon)/r2
Where G is the gravitational constant, M stands for mass, and r is the radius of the orbit. The centripetal acceleration is given by:
acentr=(4 pi2 r)/T2
Where T is the period. Since the two accelerations have to be equal, we obtain:
(4 pi2 r) /T2=G(MEarth+MMoon)/r2
Which implies:
r3/T2=G(MEarth+MMoon)/4 pi2=const.
This is the so-called third Kepler law, that states that the cube of the radius of the orbit is proportional to the square of the period.
This has interesting applications. In the Solar System, for example, if you know the period and the radius of one planet orbit, by knowing another planet's period you can determine its orbit radius. I hope that this answers your question.
True, for electricity fossil fuels are burned to turn a steam turbine to generate electricity and natural gas is exactly what it says gas formed from the decay of plant and animal life long ago
-- It takes 100 calories of heat to make 10 grams of the stuff 20° warmer.
How much of the heat warms each gram ?
-- It takes 10 calories of heat to make each gram of the stuff 20° warmer.
How much of the heat warms that gram each degree ?
-- It takes 1/2 calorie of heat to make each gram of the stuff 1° warmer.
The specific heat of that stuff is
(1/2 calorie) per gram per °C.
That's choice-3 .
Answer:
<em>-2 units of charge</em>
Explanation:
charge on A = Qa = -6 units
charge on B = Qb = 2 units
if the spheres are brought in contact with each other, the resultant charge will be evenly distributed on the spheres when they are finally separated.
charge on each sphere will be = 
charge on each sphere = 
= 
= <em>-2 units of charge</em>
