The answer is A
Materials that are good conductors of thermal energy are called thermal conductors. Metals are very good thermal conductors. Materials that are poor conductors of thermal energy are called thermal insulators. Gases such as air and materials such as plastic and wood are thermal insulators
A force of charge that drive around a circuit is call electeons
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
