Answer:

Explanation:
Area of the solar sail = A = 30 m2
Solar constant = I = 1388 W/m2
Planck's constant = h = 6.626 × 10⁻³⁴ m²kg/s
Speed of light = c = 3×10⁸ m/s
Wavelength of light =
= 570 nm
Pressure from radiation

Energy of a photon

Number of photons

Number of photons is 
Answer:
The pulse speed depends on the properties of the medium and not on the amplitude or pulse length of the pulse.
Explanation:
Hope this helps.
<u>I have assumed a weight of 120 N on Earth.</u>
Answer:
<em>The object weighs 20 N on the moon</em>
Explanation:
Weight
The weight of an object depends on the mass m of the object and the acceleration of gravity g of the place they are in.
The formula to calculate the weight is:
W = m.g
If g_e is the acceleration of gravity on Earth, and g_m is the acceleration of gravity on the moon, we know:

Dividing by ge:

An object of weight We=120 N on planet Earth has a mass of:

Multiplying by gm:

Substituting the ratio of accelerations of gravity:

Since m.gm is the weight on the Moon Wm:

The object weighs 20 N on the moon
We need optics to help aid people who have short or long sightedness.
we need optics to be able to watch TV
we need optics to be able to use the internet at high speeds
there are a tonne of reasons why we need optics.
Answer:
Decreases the time period of revolution
Explanation:
The time period of Cygnus X-1 orbiting a massive star is 5.6 days.
The orbital velocity of a planet is given by the formula,
v = √[GM/(R + h)]
In the case of rotational motion, v = (R +h)ω
ω = √[GM/(R + h)] /(R +h)
Where 'ω' is the angular velocity of the planet
The time period of rotational motion is,
T = 2π/ω
By substitution,
<em>T = 2π(R +h)√[(R + h)/GM] </em>
Hence, from the above equation, if the mass of the star is greater, the gravitational force between them is greater. This would reduce the time period of revolution of the planet.