Answer:
The energy stored in the solenoid is 0.18J
Explanation:
We need to obtain the inductance in order to calculate the energy:

The energy stored in the solenoid is given by:

Answer:
The net force exerted by these two charges on a third charge is 
Explanation:
Given that,
Third charge 
Distance
Suppose The magnitude of the force F between two particles with charges Q and Q' separated by a distance d. Consider two point charges located on the x axis one charge, q₁ = -12.5 nC , is located at x₁ = -1.650 m, the second charge, q₂ = 31.5 nC , is at the origin.
We need to calculate the total force will be the vector sum of two forces
Using Coulomb's law,

Put the value into the formula


We need to calculate the force will be to the negative charge with opposite charges
Using Coulomb's law,

Put the value into the formula


The force also will be to the negative side, charges with same charge sign
We need to calculate the net force exerted by these two charges on a third charge
Using formula of net force




Negative sign shows the negative direction.
Hence, The net force exerted by these two charges on a third charge is 
Work formula is Work=N∙M or Joule (J)
So you have the following given:
50 000 is the output work
.8 is the efficiency
if you input the given = 50000 = .8*J
To get the answer just divide 50000 by .8 to get the answer.
62,500 J is the amount of work to be done.
Answer:
When the voltage is at a maximum positive value, the the current is at a value that is maximum and positive
Explanation:
We know that the relation between the Voltage and the current is given using the Ohm's law, which states that the voltage (V) is directly proportional to the current (I)
Mathematically,
V ∝ I
Hence,
When the voltage is at a maximum positive value, the the current is at a value that is maximum and positive
Answer:
d = .076 m
Explanation:
The time for frog A can be calculated from equation of motion

where v_f is final velocity, a is acceleration due to gravity
so from given data we have

t = 0.112 sec
Now we will use that time for frog B


(Note its positive)
For the displacement


d = .076 m