Traveling against currents usually takes longer. Kinda like walking against the wind, you feel the heaviness against your jacket as you push through it. Where when you walking with the wind, it kind of gives your a push. Same for with currents.
The velocity is 60 because you divide your distance by your time (240÷4=60)
<span>We see only one side of the moon from earth because the moons period of rotation and revolution are equal. The moon rotates around the Earth at the exact speed as it rotates around its won axis (revolution). The result is: the same side of the moon is facing the Earth. If the moon doesn't rotate on it's axis we on the Earth would see all of the sides of the Moon.</span>
Since there are no choices, then this question calls for open-ended answers. Facts-based science must have proven underlying laws that support inferences such as Coulomb's Law, Kinetic Theory of Matter and many more. On the other hand, examples of science that focus on personal belief is philosophy. This depends on the perspective of known philosophers. An example would be Sigmund Freud who proposed the theory of 3 personalities. Although it is more on personal beliefs, this is used as a foundation in the study of psychology.
Answer:

Explanation:
The constant speed means that ball is not experimenting acceleration. This elements is modelled by using the following equation of equilibrium:


Now, the exerted force is:

The volume of a sphere is:



Lastly, the force is calculated:

