Ohms law = v= Ir
V= 0.02 x 4000 = 80v
Answer:
Explanation:
i )
When it is disconnected with the battery , the charge stored in it becomes fixed . When the plate distance becomes half , its capacitance becomes twice from C to 2C . Let charge stored in it at the time of disconnection from battery be Q . Let plate separation reduces from d to d / 2
So charged stored in it will remain unchanged .
ii )
Potential difference = charge / capacitance
in the first case potential difference = Q / C
in the second case potential difference = Q / 2C
So potential difference becomes half .
iii ) electric field = potential diff / plate separation
in the first case electric field = Q / (d x C )
in the second case electric field = 2 Q / (d x 2C)
= Q / (d x C )
So electric field remains unchanged .
iv)
energy stored in first case = Q² / 2C
In the second case energy stored = Q² / 2x2C
so energy stored becomes half .
Answer:
The initial speed of the pelican is 8.81 m/s.
Explanation:
Given;
height of the pelican, h = 5.0 m
horizontal distance, X = 8.9 m
The time of flight is given by;
The initial horizontal speed of the pelican is given by;
X = vₓt
vₓ = X / t
vₓ = 8.9 / 1.01
vₓ = 8.81 m/s
Therefore, the initial speed of the pelican is 8.81 m/s.
The kinetic energy of the phone right before it hits the ground is 9J.
<h3>
Kinetic energy of the phone</h3>
The kinetic energy of the phone right before it hits the ground is calculated as follows;
K.E = ¹/₂mv²
where;
- m is mass of the phone
- v is velocity of the phone
K.E = ¹/₂(0.08)(15)²
K.E = 9 J
Thus, the kinetic energy of the phone right before it hits the ground is 9J.
Learn more about kinetic energy here: brainly.com/question/25959744
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