Elliptical, because the shape of the galaxy isn’t like the others. It is unique to its own and doesn’t have another to compare to
I think the correct answer is true. Most paper does not reflect light very well because its surface is somewhat rough. Light only reflects to surfaces which has a smooth texture or have a uniform texture on the surface. Hope this answers the question. Have a nice day.
Answer:
Explanation:
Speed of skier without parachute
= √ 2gh
= √ 2 x 9.8 x 35
= 26.2 m / s
Speed of skier with parachute
net force downwards
mg - 200
= 60 x 9.8 -200
= 388 N
acceleration = 388 / 60
a = 6.47 m / s
v = √ 2ah
= √ 2 x 6.47 x 35
= 21.28 m / s
Answer:
c) The wavelength decreases but the frequency remains the same.
Explanation:
Light travels at different speed in different mediums.
Refractive index is equal to velocity of the light 'c' in empty space divided by the velocity 'v' in the substance.
Or ,
n = c/v.
<u>The frequency of the light does not change but the wavelength of the light changes with change in the speed.</u>
c = frequency × Wavelength
Frequency is constant,
The formula can be written as:
n = λ / λn.
Where,
λn is the wavelength in the medium
λ is the wavelength in vacuum
<u>When the light travels to glass, it speed slows down and also the wavelength decreases as both are directly proportional. There will be no effect on frequency.</u>
Answer:
The value of the average convection coefficient is 20 W/Km².
Explanation:
Given that,
For first object,
Characteristic length = 0.5 m
Surface temperature = 400 K
Atmospheric temperature = 300 K
Velocity = 25 m/s
Air velocity = 5 m/s
Characteristic length of second object = 2.5 m
We have same shape and density of both objects so the reynold number will be same,
We need to calculate the value of the average convection coefficient
Using formula of reynold number for both objects
Here, 
Put the value into the formula
Hence, The value of the average convection coefficient is 20 W/Km².
