Answer:
A. Materials with a low index of refraction cause light to refract very little.
The name and strength of the force holding the block up is 50 N upward - Normal force.
The given parameters:
- <em>Mass of the block, m = 5 kg</em>
The weight of the block acting downwards due to gravity is calculated as follows;
W = mg
where;
- <em>g is acceleration due to gravity = 10 m/s²</em>
W = 5 x 10
W = 50 N <em>(</em><em>downwards</em><em>)</em>
Since the block is at rest, an a force equal to the weight of the block must be acting upwards. This force is known as normal reaction.
Fₙ = 50 N <em>(</em><em>upwards</em><em>)</em>
Thus, the name and strength of the force holding the block up is 50 N upward - Normal force.
Learn more about Normal force here: brainly.com/question/14486416
Answer:
<h3>2,321.62Joules</h3>
Explanation:
The formula for calculating workdone is expressed as;
Workdone = Force * Distance
Get the force
F = nR
n is the coefficient of friction = 0.5
R is the reaction = mg
R = 46 ( 9.8)
R = 450.8N
F = 0.5 * 450.8
F = 225.4N
Distance = 10.3m
Get the workdone
Workdone = 225.4 * 10.3
Workdone = 2,321.62Joules
<em>Hence the amount of work done is 2,321.62Joules</em>
By definition we have to:
The electric current is the flow of electric charge due to the movement (usually of electrons) that a material travels.
Some properties are:
1) Electric conduction: The conductive materials have a large amount of free electrons, therefore, the passage of electricity is possible.
2) The current inside a circuit is directly proportional to the voltage and inversely proportional to the resistance of the circuit. This is what is known as ohm's law:

3) The current can be continuous or alternate.
Alternating current is the electric current in which the magnitude and direction vary cyclically.
The direct current is the flow of electric charges that does not change direction with time.