Answer:
If I am correct, the answer is D. Law of conservation of energy
Explanation:
the potential energy "converts" to kinetic once Luke is in motion.
The formula for acceleration is the velocity times the inverse of time so it would be 21 times 1/13. So roughly 0.0769... is the acceleration(m/s^2).
Answer:
<em>b. Observe the radio waves coming from all dark matter; from the strength of the radio waves from each cluster, estimate the amount of dark matter needed to produce them.</em>
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Explanation:
The universe is thought to be made up of 85% dark matters. <em>Dark matter is called dark because it does not appear to interact with the electromagnetic field, which means it doesn't absorb, reflect or emit electromagnetic radiation, and is therefore difficult to detect. This means that option b is wrong since radio wave is an electromagnetic wave</em>. Dark matter is a form of matter that makes up about a quarter of the total mass–energy density of the universe. Dark matter was theorized due a variety of astrophysical observations and gravitational effects that cannot be explained by accepted theories of gravity unless there were more matter in the universe than can be seen.
Answer:
Explanation:
Given
mass of sphere 
diameter of sphere 
radius 
friction will provide resisting torque so
where 
(b)time taken to decrease its rotational speed by 
