Hi there! :)
In the solar system, we can categorize the planets as such:
Inner planets: Mercury, Venus, Earth, Mars
Outer planets: Jupiter, Saturn, Uranus, Neptune
The Inner planets are the only planets that consist of solid rock. They also do not have rings and have impact craters due to their early formation.
In comparison, all of the outer planets are primarily made up of gaseous material and contain rings.
Therefore, the correct choice is B.
Answer:
c. 3/2 mg
Explanation:
Given that the acceleration of an elevator is 1/2 g upward.
The reading on the scale of the elevator is the net external force acting on the elevator.
Let the force F acting on the elevator as shown,
By using Newton's 2nd law,
where, is the net force acting on the elevator.
m is the mass of the elevator,
a is the acceleration of the elevator, as given a=1/2 g upward.
So,
So, the reading on the scale in the elevator is .
Hence, option (c) is correct.
Answer:
a) M = 2 10³⁰ kg
, b) = 5.81 10⁷ s
Explanation:
a) For this exercise let's use Newton's second law where force is the law of universal gravitation and acceleration is centripetal
G m M / R² = m a
a = v² / R
G M / R = V²
The orbit of the two planets is approximately circular, therefore the velocity module (speed) is constant
v = d / t
The distance is the length of the circular orbit
d = 2π R
G M / R = 4π² R² / T²
G M T² = 4π² R³
Let's write this equation for each planet
For the earth
The period is T = 3.16 10⁷ s and the radius of the orbit R = 1.5 10¹¹ m, let's calculate the mass of the sun
M = 4π² R³ / G T²
M = 4π² (1.5 10¹¹)³ / (6.67 10⁻¹¹ (3.16 10⁷)²)
M = 133.24 10³³ / 66.60 10³
M = 2 10³⁰ kg
b) For this part we write this equation for the two points
For the earth
² = (4π² / G M)
³
For mars
² = (4π² / G M)
³
Let's divide the two expressions
² /
² =
³ /
³
They indicate that the orbit of Mars is = 1.5
² /
² = (1.5
/
)³
² =
² 1.5³
² = (3.16 10⁷)² 1.5³
= √ (33.70 10¹⁴)
= 5.81 10⁷ s