The question is poor.
It expects you to choose 'B', but things aren't nearly that simple.
We picture all of the asteroids bunched up in a neat bunch between
the orbits of Mars and Jupiter, with each asteroid following its own
nearly circular orbit. But many asteroids have wildly non-circular
'eccentric' orbits, sometimes being closer to the sun than the Earth is.
You know how you hear so much discussion about when did the Earth
get hit by an asteroid ? and when will the Earth be hit by another asteroid ?
and what will happen when the Earth is hit by an asteroid again ? None
of that would be possible if asteroids all had nearly circular orbits.
We picture comets as having these loooong skinny orbits, spending
most of every orbit waaay out in the solar system, and then dipping
close to the sun for a few days, and then going back waaaay out again.
But there are also many comets in nearly circular orbits around the sun.
You never hear anything about them, because you can never see them
without a powerful telescope, and they never do anything exciting.
So some comets could be a correct answer to this question too.
And since meteoroids are the remains of old comets, and follow the
orbit of the comet that they chipped off from, there are a lot of meteoroids
in circular orbits too, and they could also be a correct answer to this question.
Answer:
C. It triples in magnitude (PLATO)
Given Information:
Mass of elephant = m = 750 kg
Height = h = 14.3 m
time = t = 30 seconds
Required Information:
Power needed to lift elephant = P = ?
Answer:
Power needed to lift elephant ≈ 3507 watts
Explanation:
As we know power is given by
P = PE/t
Where PE is the potential energy and t is the time
Potential energy is given by
PE = mgh
Where m is the mass of elephant, g is the gravitational acceleration and h is the height to lift the elephant.
PE = 750*9.81*14.3
PE = 105212.25 Joules
Therefore, the required power to lift the elephant is
P = PE/t
P = 105212.25/30
P ≈ 3507 watts
Answer:
tire marks are due to the increase in thermal energy
Explanation:
When a tire is spinning at a given speed when the brakes are applied hard, the friction between the tire's particulate and the ground surface is high enough that some tire particles are transferred to the ground.
This is reflected in the heat transfer from the tire to the ground.
Consequently, tire marks are due to the increase in thermal energy and the change in the friction force of the tire.
The star is FARTHER from Earth than the limit of our ability to measure parallax.
The NEAREST star outside the solar system has a parallax angle of 0.742 SECOND. That's like 0.000206 of a degree ! ALL other stars have SMALLER parallax.
I have no idea how they measure angles like these ... especially when the change in direction takes six months to happen !
