Answer:
for question no.4,
time =6 secs
acceleration due to gravity (g)= 9.8 m/s^2
velocity=gt
=6×9.8
=58.8m ans...
for question no .5,
time taken = 4seconds
aacceleration due to gravity (g)=9.8 m/s^2
distance=12gt
=12×9.8×4
=470.4meter answer...
<span>Disadvantages:
One of the main disadvantages is the initial cost of the equipment used
to harness the suns energy. Solar energy technologies still remain a
costly alternative to the use of readily available fossil fuel
technologies. As the price of solar panels decreases, we are likely to
see an increase in the use of solar cells to generate electricity.
A solar energy installation requires a large area for the system to be
efficient in providing a source of electricity. This may be a
disadvantage in areas where space is short, or expensive (such as inner
cities).
Pollution can be a disadvantage to solar panels, as pollution can
degrade the efficiency of photovoltaic cells. Clouds also provide the
same effect, as they can reduce the energy of the suns rays. This
certain disadvantage is more of an issue with older solar components, as
newer designs integrate technologies to overcome the worst of these
effects.
Solar energy is only useful when the sun is shining. During the night,
your expensive solar equipment will be useless, however the use of solar
battery chargers can help to reduce the effects of this disadvantage.
The location of solar panels can affect performance, due to possible obstructions from the surrounding buildings or landscape.
</span>
Answer:he is incorrect
Explanation:he is wrong because if the sunlight is on the opposite side of the earth than the moon, then the sunlight would be blocked by the earth, making the moon dark, because the moon gets its light from the light that is reflected of the surface from the sun
Answer:
V= 4999.5 m/s
Explanation:
Given that
mass ,m= 605 gm
Length ,L= 0.75 m
width ,b= 0.01 m
height ,h= 0.03 m
frequency ,f= 3333 Hz
We know that
2 Length = Wavelength
λ= 2 x L
λ = 2 x 0.75 m
λ= 1.5 m
The speed V
V= f x λ
Now by putting the values
V= f x λ
V= 3333 x 1.5 m/s
V= 4999.5 m/s