A natural force of attraction exerted by the earth upon objects, that pulls objects towards earth's center is called<u> </u><u>G</u><u>ravitational</u><u> </u><u>force</u><u> </u><u>.</u>
Answer:
both magnesium and strontium have 2 valence electrons
Explanation:
potassium has 8 valence electrons, and nitrogen has 5.
Answer:
5 m/s2, left
Explanation:
We can solve the problem by applying Newton's second law of motion, which states that:
where:
is the net force acting on an object
m is the mass of the object
a is its acceleration
In this problem, we have:
(to the left) is the net force on the object
m = 2.0 kg is the mass
So, the acceleration is:
in the same direction as the force (left).
Answer:
30 degrees
Explanation:
Reflects off of mirror 1 at 60 degrees....this makes it incident to second mirror at 30 degrees ....then angle of reflection equals this angle of incidence = 30 degrees
See atached diagram
Answer:
<em>d. The sail should be reflective because in this case the momentum transferred to the sail per unit area per unit time is larger than for absorbing sail, therefore the radiation pressure is larger for the reflective sail.</em>
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Explanation:
Let us take the momentum of a photon unit as u
we know that the rate of change of momentum is proportional to the force exerted.
For a absorbing surface, the photon is absorbed, therefore the final momentum is zero. From this we can say that
F = (u - 0)/t = u/t
for a unit time, the force is proportional to the momentum of the wave due to its energy density. Therefore,
F = u
For a reflecting surface, the momentum of the wave strikes the sail and changes direction. Since we know that the speed of light does not change, then the force is proportional to
F = (u - (-u))/t = 2u/t
just as the we did above, it becomes
F = 2u.
From this we can see that the force for a reflective sail is twice of that for an absorbing sail, and we know that the pressure is proportional to the force for a given area. From these, we conclude that <em>the sail should be reflective because in this case the momentum transferred to the sail per unit area per unit time is larger than for absorbing sail, therefore the radiation pressure is larger for the reflective sail.</em>
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