Answer:
The answer to your question is 784.8 J. None of your answer, did you forget some information?
Explanation:
Data
mass = 20 kg
distance = 4 m
work = ?
Formula
Work = force x distance
Force = mass x gravity
Process
1.- Calculate the weight of the block
Weight = 20 x 9.81
Weight = 196.2 N
2.- Calculate the work done
Work = 196.2 x 4
Work = 784.8 J
To solve this problem it is necessary to apply the equations related to the conservation of momentum. Mathematically this can be expressed as

Where,
= Mass of each object
= Initial velocity of each object
= Final Velocity
Since the receiver's body is static for the initial velocity we have that the equation would become



Therefore the velocity right after catching the ball is 0.0975m/s
Answer:
Change in electric potential energy is -28.0 J
Explanation:
Electric potential energy is defined as the work is done to move a charge particle from one position to another in space in the presence of other charge particle or electric potential.
OR
Electric potential energy is also equal to the change in the configuration of the charge particles.
Thus,
Change in electric potential energy = - Work Done
According to the problem, Work Done is equal to 28 J. Thus,
Change in electric potential energy = -28 J
Answer:
Explanation:
In a conductor, electric current can flow freely, in an insulator it cannot.
Metals such as copper typify conductors, while most non-metallic solids are said to be good insulators, having extremely high resistance to the flow of charge through them.
Most atoms hold on to their electrons tightly and are insulators.
Answer:
The new force becomes 4 times the initial force.
Explanation:
The force of attraction or repulsion is given by the relation as follows :

Where
d is the distance between the interacting charges
F is inversely proportional to the distance between charges.
If the distance is halved, d'=(d/2), new force is given by :

So, the new force becomes 4 times the initial force.