Answer:
(A)
Explanation:
We know , electric potential energy between two charge particles of charges "q" and "Q" respectively is given by kqQ/r where r is the distance between them.
Since the two charged particles are moving apart, the distance between them (r) increases and thus electrical potential energy decreases.
Answer:
¹/₃₈₇ second
Explanation:
<em>The period of a wave is the reciprocal of its frequency.</em>
So, simply, the frequency is ¹/₃₈₇ second(s), as that is the reciprocal of the frequency, 387 Hz.
Answer:
6480 km
Explanation:
The speed of the object is
v = 7500 cm/sec
We need to convert centimetres into kilometers and seconds into days. We have:


Using these conversion factors, we find:

1. C. Gravitational attraction exists between the two objects.
Explanation:
Gravitational attraction is always exerted between two objects which have mass, and its magnitude is given by:

where G is the gravitational constant, m1 and m2 the masses of the two objects, and r the separation between them. Since the two objects have for sure non-zero masses m1 and m2, even if they are 20 miles apart, the value of the gravitational attraction F is non-zero, so the correct answer is C.
2. D. Two atoms come together to form a molecule.
Explanation:
this outcome is actually caused by the electrostatic forces between the two atoms, not by gravitational force. In fact, gravitational force becomes relevant only when the masses of the two objects involved are large enough: this is the case for planets, stars, galaxies, and objects in the universe. However, two atoms have very small masses, so the gravitational force between them is really negligible. On this smaller scales, the electrostatic force is much stronger than the gravitational force, so the electrostatic force is the real responsible for the formation of bonds between atoms.
Answer:
Condensation
Explanation:
That is when water from the air collects as a drop. also can be rain.