Answer:
D. They don't require a medium to travel through.
Explanation:
Electromagnetic waves and mechanical waves are both types of waves. Electromagnetic waves are waves that arise from the combination of electric and magnetic fields while mechanical waves are waves that arise as a result of transfer of energy via matter.
One major difference between these two types of waves is that electromagnetic waves such as light waves, radiowaves etc. do not need a medium to travel i.e. they can travel through a vacuum, while on the other hand, mechanical waves such as sound waves need a medium to travel.
<span>c. increases across a period and decreases down a group.</span>
The force on a unit positive charge at the given position is determined as 1.8 x 10⁻⁸ N.
<h3>Force on the charge</h3>
The force on the charge is calculated as follows;
F = k(q1q2)/r²
where;
- r is the distance between the charges = 2 m - 1m = 1m
F = (9 x 10⁹ x 10⁻⁹ x 2 x 10⁻⁹)/(1)²
F = 1.8 x 10⁻⁸ N
Thus, the force on a unit positive charge at the given position is determined as 1.8 x 10⁻⁸ N.
Learn more about force here: brainly.com/question/12970081
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Because one side of the spoon is convex and the other side is concave, the spoon’s different sides reflect differently.