Answer:
Average speed is 60 km/hour
Explanation:
When we need to calculate average speed, we use this equation:
Where: 
position at the beginning
at the end
Then: 
Finally V = 60 km/hour
Answer:
A) Its density will decrease
Explanation:
When an object is heated, its volume increases. This is due to the fact that the particles in the medium vibrate more (if it is a solid) or they move more (if it is a liquid or a gas), therefore they tend to occupy a larger space.
At the same time, the mass of the object does not change, because the mass just represents the amount of matter contained in the object, so it does not increase/decrease at different temperatures.
The density of an object is defined as the ratio between the mass (m) and the volume (V):
We said that the mass remains unchanged while the volume increases: since the density is inversely proportional to the volume, this means that the density decreases.
Applying Newtons version of Kepler's third law or the orbital velocity law to the star orbiting 40000 light years from the center of the Milky Way Galaxy allows us to determine the mass of the Milky Way Galaxy that lies within 40000 light years in the galactic center.
<h3>
</h3><h3>What is orbital velocity law?</h3>
The orbital velocity law states that, the orbital velocity is directly proportional to the mass of the body for which it is being calculated and inversely proportional to the radius of the body. Earths orbital velocity near its surface is around 8km/sec if the air resistance is disregarded.
In space exploration, orbital velocity is a crucial topic. Space authorities heavily rely on it to comprehend how to launch satellites. It aids scientists in figuring out the velocities at which satellites must orbit a planet or other celestial body to prevent collapsing into it. The speed at which one body orbits the other body is known as the orbital velocity. The term "orbit" refers to an object's consistent circular motion around the Earth. The distance between the object and the earth's centre determines the orbit's velocity.
To know more about orbital velocity law, refer brainly.com/question/11353717
#SPJ4
