You already told us that its speed is constant. That's one part of acceleration.
The other part of acceleration is the direction it's moving.
If it's rolling in a straight line, then there's no acceleration.
If it's curving left or right, then that's acceleration.
Here, you can derive that by numerical method, as follows:
F = m.a
m = F/a
So, here we can see when we decrease one, other increase by same effect; we can say they are "Indirectly Proportional" to each other!
Hope this helps!
Explanation:
Dark Energy is a property of the entire universe. And the universe is roughly made up of 68% of this dark energy whereas dark matter makes up 27% of the universe matter.
The influence of the dark matter shows in the individual galaxies whereas dark energy acts only on the entire universe. dark matter is responsible for the gravity effect on the plants and the heavenly bodies which produces gravity force. But the dark energy is known as the anti gravity force as it is responsible for the expansion of the universe. Dark matter attracts and produces an attractive force while dark energy repels and produces a repulsive force.
Scientist believe that they exists to account for the very fact that gravity holds all the heavenly bodies and the galaxies together. They are even responsible for the fluctuation in Cosmic Microwave background. Researchers and scientist firmly believe that all the visible matter that exists may not have enough gravitational pull to hold everything together in the galaxies. And also the expanding universe strongly proves that dark energy exists in the universe.
So you subtract the numbers that are on the same axis. So if your gravitational force is 10 and your normal force is 5 you do 5-10 to get -5 since gravity acts downward
Light from the stars, because the orbits make it difficult to see them.
