To contrast inner and outer planets we will start with the climate of the planets and then move on to there lighting. To start the planets closet to the sun, mercury, venus, earth and mars, are all hot compared to the further one, jupiter, saturn, uranus, neptune. This distance also makes the farthe away planets darker than the ones closer. Now to compare all the planets vary from either gass or solid, rocky or icy. All of them spin around the sun and all have objects spinning around them, moons.
Answer:
v = 18.84 m/s
Explanation:
Given that,
The length of the string, r = 1.5 m (it will act as radius)
The rubber stopper makes 120 complete circles every minute.
Since, 1 minute = 60 seconds
It means, its frequency is 2 circles every second.
Let we need to find the average speed of the rubber stopper. It can be calculated as follows :

d is distance,
and 1/T = f (frequency)

So, the average speed of the rubber stopper is 18.84 m/s.
The only vertical forces are weight and normal force, and they balance since the surface is horizontal. The horizontal forces are the applied force (uppercase F) in the direction the block slides and the frictional force (lowercase f) in the opposite direction.
Apply Newton's 2nd Law in the horizontal direction:
ΣF = ma
F - f = ma
where f = µmg
F - µmg = ma
F = m(a +µg)
F = (20 kg)(1.4 m/s² + 0.28(9.8 m/s²)
F = 83 N
Answer:
The photon has a wavelength of
Explanation:
The speed of a wave can be defined as:
(1)
Where v is the speed,
is the frequency and
is the wavelength.
Equation 1 can be expressed in the following way for the case of an electromagnetic wave:
(2)
Where c is the speed of light.
Therefore, 
can be isolated from equation 2 to get the wavelength of the photon.
(3)

Hence, the photon has a wavelength of
<em>Summary: </em>
Photons are the particles that constitutes light.
So the answer is B. because the mass have Kg as a international unit and velocity is m/s, they are international units in physics.