Answer: 
Explanation:
Given
Magnitude of charge is 
Force experienced is 
Electric field intensity is the electrostatic force per unit charge

Thus, the electric field intensity is 
Answer:b
Explanation:
Given
mass of heavy object is 4m
mass of lighter object is m
A person pushes each block with same force F
According to Work Energy theorem Change in kinetic energy of object is equal to Work done by all the object
As launching velocity is same for both the object so heavier mass must possess greater kinetic energy . For same force heavier mass must be pushed 4 times farther than the light block .


So the correct option is b
Answer:
3099 J
Explanation:
The increase in thermal energy corresponds to the mechanical energy lost in the process.
The mechanical energy is given by the sum of gravitational potential energy and kinetic energy of the fireman:

At the top of the pole, the fireman has no kinetic energy, so all his mechanical energy is just potential energy:

When the fireman reaches the bottom, he has no gravitational potential energy, so his mechanical energy is just given by his kinetic energy:

So, the loss in mechanical energy was

and this corresponds to the increase in thermal energy.