Answer:
-0.5 m/s^2
Explanation:
Acceleration = change in velocity / total time
7.5 / 15 = 0.5
Its readily available
No Harmful emissions
Environment friendly
Renewable
Hydrogen isn't very good fuel source due to its high flammability and can create a nasty mini hydrogen bomb. <span />
Answer:
The distance between the two objects must be squared.
Explanation:
Gravitational force always act between two objects that have mass. The gravitational force is a weak force and attractive in nature.
The force of pull depends on the masses of the two objects and the distance between them.
The formula to calculate gravitational force between two objects having masses 'm' and 'M' and separated by a distance 'd' is given as:

Where, 'G' is called the universal gravitational constant and its value is equal to
.
Now, from the above formula, it is clear that, the force of gravitation is inversely proportional to the square of the distance between the two objects.
Thus, the quantity that must be squared in the equation of gravitational force between two objects is the distance 'd'.
The sound is perceived as louder if the amplitude increases, and softer if the amplitude decreases. ( for amplitude)
Since sound at all frequencies has the same speed in air, a change in frequency means a change in wavelength. ( for frequency)
Answer:
D) Fusion requires high temperatures and pressures, so how have they reduced the energy cost for it?
Explanation:
Fusion requires high temperatures and pressure for initiation of reaction . There is no chain reaction in it so there is no problem of controlling the problem . On the other hand , the reaction tends to stop as soon as temperature goes down due to heat getting dissipated . There is no problem of fuel as its fuel is deuterium which is present in nature in large amount . The question which is pertinent is that the cost involved in attaining so high temperature is very high so is it cost effective to produce energy by incurring so much of cost . Producing energy by using so much of energy in the beginning appears to be preposterous.