No light does not need medium to travel.Its an electromagnetic(EM) wave.All EM waves travel independent of medium. In contrast mechanical waves need a medium,sound waves,shock waves are mechanical and they need medium to transfer energy or travel.
In science, a broad idea that has been repeatedly verified so as to give scientists great confidence that it represents reality is called "a theory".
<u>Explanation:</u>
In science, the interpretation of a feature of the organic world that can be tested in repeat manner and analysed by applying agreed tests validation methods, calculation and observation in according to the scientific method, such process is called as a theory in science.
The difference lie between a theory and a hypothesis. Because hypothesis is an "educated guess". Overall it is either a proposed interpretation of an observed phenomenon, or a logical inference of a possible causal association between several phenomena.
That Energy Cannot Be Created Nor Destroyed
Answer:
11.0 kg m/s
Explanation:
The impulse exerted on the cart is equal to its change in momentum:

where
m = 5.0 kg is the mass of the cart
is its change in speed
Substituting numbers into the equation, we find

The answer is: Heat can<span> be </span>transmitted<span> though </span>empty space<span> by thermal radiation. Thermal radiation (often called infrared radiation) is a type electromagnetic radiation (or light). Radiation is a form of energy transport consisting of electromagnetic waves traveling at the speed of light.</span>