<h2>
Answer: 56.718 min</h2>
Explanation:
According to the Third Kepler’s Law of Planetary motion<em> </em><em>“The square of the orbital period of a planet is proportional to the cube of the semi-major axis (size) of its orbit”.
</em>
In other words, this law states a relation between the orbital period
of a body (moon, planet, satellite) orbiting a greater body in space with the size
of its orbit.
This Law is originally expressed as follows:
(1)
Where;
is the Gravitational Constant and its value is
is the mass of Mars
is the semimajor axis of the orbit the spacecraft describes around Mars (assuming it is a <u>circular orbit </u>and a <u>low orbit near the surface </u>as well, the semimajor axis is equal to the radius of the orbit)
If we want to find the period, we have to express equation (1) as written below and substitute all the values:
(2)
(3)
(4)
Finally:
This is the orbital period of a spacecraft in a low orbit near the surface of mars
Answer:
(a) Time t = 16.46 sec
(b) Time t =13.466 sec
(c) Deceleration = 
Explanation:
(a) As the train starts from rest its initial velocity u = 0 m/sec
Acceleration 
Final speed v = 80 km/hr

From first equation of motion v =u+at
So 
(b) Now initial speed u = 22.22 m/sec
As finally train comes to rest so final speed v=0 m/sec
Deceleration 
So 
(c) We have given that initial velocity = 80 km/hr = 22.22 m/sec
Final velocity v = 0 m/sec
Time t = 8.30 sec
So acceleration is given by

As acceleration is negative so it is a deceleration
Light travels faster than sound ,because sound can only travel waves.
Kepler's laws were enunciated to model in a mathematical way the movement of the planets in their respective orbits around the Sun.
There are three laws of Kepler.
In particular, Kepler's first law states the following:
"All the planets move around the Sun describing elliptical orbits, the Sun is in one of the foci of the ellipse."
Answer:
Kepler's 1st law of planetary motion states that the planets have an elliptical orbit, with the Sun at one focal point of the ellipse.
a. 1st law
Answer:
A maximum
Explanation:
When displacement is maximum, velocity is Zero and vice versa
When displacement is maximum, acceleration is maximum and when it is zero, acc. Is zero