The answer is the first one. That's because the general theory of relativity is the thing experiencing whatever is experiencing relative to something else. The second answer is just plain wrong. The third answer is just a constant, and doesn't relate to experiencing anything. And the fourth answer is a force between two objects, and it has no second comparison. The first answer is how a subject experiences two different things.
The sled experiences friction against the ground
Answer:
Solution given:
velocity=40cm/s
wave length=5cm
we have
frequency =velocity/wavelength=40/5=8hertz.
the frequency of the <u>wave</u><u> </u><u>i</u><u>s</u><u> </u><u>8</u><u> </u><u>h</u><u>e</u><u>r</u><u>t</u><u>z</u><u>.</u>
Answer:
First answer.
Explanation:
There may be a 5N force, but if the frictional force also equals 5N, than they cancel eachother out, resulting in the brick still staying still, as it is resting on a (perfectly) level surface, but any amount of force would make the brick move.