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
To Make I the subject you need to get it by itself. To do this divide both sides by V and t:
I = E/Vt
In order to change the direction and speed, a net external force is required. A net external force is an unbalanced force which will change the direction and gives the speed in the opposite direction. Hence, its an unbalanced force from the joey that pushes the car in the other direction due to which it the car starts to move back to Leah. Without, unbalanced force there is not change in the direction of the car's motion.
Hence, option B is correct.