Answer:
Sound energy to electric energy - a person talking into a microphone
Radiant energy to electric energy - sunlight falling on solar panels
Gravitational potential energy to motion energy - a ball dropped from a height
Explanation:
A person talking is the sound energy and going into an electric phone
Sunlight or Radiant energy falls onto the solar panels creating electric energy
The ball is being pulled down by gravity from a certain height, going down to the ground, it’s motion, falling
The two letters are B and A, in that order.
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>
<em></em>
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>
<em></em>
Answer:
radius r is 0.414 R
Explanation:
Given data
FCC octahedral site
atomic radius R
to find out
radius r
solution
we know that at FCC octahedral
length of side = 2 R + 2r
and by pythagorean theorem
a = 2√2R
here a = 2R + 2r
so 2R + 2r = 2√2R
so r = ( √2R )- R
r = 0.414 R
so radius r is 0.414 R
Answer:
5.42 s
Explanation:
Using the equation of motion,
v = u + at ..................... Equation 1,
Where v = Final velocity, u = initial velocity, a = acceleration, t = time.
Making t the subject of the equation,
t = (v-u)/a ....................... Equation 2
Note: When the the bicycle is brought to a complete stop, the final velocity of the bicycle is 0 m/s and the bicycle is decelerating.
Given: v = 0 m/s, u = 6.5 m/s, a = - 1.2 m/s² ( decelerating).
Substituting into equation 2
t = (0-6.5)/-1.2
t = -6.5/-1.2
t = 5.42 s.
Hence the time take for the cyclist to bring the bicycle to complete stop = 5.42 s
