<em>The correct option is </em><em>A</em>. The information we know about the known exoplanets is estimates of orbits and masses.
<h3>What is exoplanets?</h3>
An exoplanet or extrasolar planet is a planet outside the Solar System.
In other words, exoplanet is any planet beyond our solar system. 
<h3>Characteristics of exoplanets</h3>
exoplanets are known for the following characteristics;
- they are usually hot
- they can orbit their stars so tightly that a “year” lasts only a few days
- they can orbit two suns at once
Thus, the information we know about the known exoplanets is estimates of orbits and masses.
Learn more about exoplanets here: brainly.com/question/1514493
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Answer:
it is ---D because you can't measure gas and it's mass
HOPE THIS HELPS
 
        
             
        
        
        
Answer:
Explanation:
Given height of lamp from the ceiling = 2.6m
mass of the lamp = 3.8kg
acceleration due to gravity = 9.81m/s²
As the body falls to the ground, it falls under the influence of gravity.
Gravitational potential energy = mass*acc due to gravity * height
Gravitational potential energy  = 3.8*2.6*9.81
Gravitational potential energy  = 96.923 Joules
b) Kinetic energy = 1/2 mv²
m = mass of the body (in kg)
v = velocity of the body (in m/s²)
To get the velocity v, we will use the equation of motion 

Since mass = 3.8kg

c) To know how fast the lamp is moving when it hits the ground, we will use the formula. When the body hits the ground, the height covered will be 0m. this means that the body is not moving once it hits the ground. It stays in one position. The energy possessed by the body at this point is potential energy. The correct answer is therefore 0 m/s