Answer:
Explanation:
The strength of an electric field E produced by a single charge Q at a distance d from it is given by the formula: , where K represents the Coulomb constant.
Since the electric field E is derived from the Coulomb Force per unit charge using a positive test charge, the field's units will be in units of Newtons/Coulomb, and be the formula for the Coulomb electric force between to charges (Q1 and Q2),
but modified with only one charge showing in the numerator of the expression.
Answer:
7350 J
Explanation:
The gravitational potential energy of the rock sitting on the edge of the cliff is given by:
where
m is the mass of the rock
g is the gravitational acceleration
h is the height of the cliff
In this problem, we have
m = 50 kg
g = 9.8 m/s^2
h = 15 m
Substituting numbers into the formula, we find:
a) Average power: 1425 W
b) Instantaneous power at 3.0 sec: 2850 W
Explanation:
a)
The motion of the object along the ramp is a uniformly accelerated motion (because the force applied is constant), so we can use the suvat equation
where
s = 18 m is the displacement along the ramp
u = 0 is the initial velocity
t = 3.0 s is the time taken
a is the acceleration of the object along the ramp
Solving for a,
Now we can apply Newton's second law to find the net force on the object:
This net force is the resultant of the applied force forward () and the component of the weight acting backward (
), so we can find what is the applied force:
where
m = 24 kg is the mass of the object
is the acceleration of gravity
Now we can finally find what is the work done by the applied force, which is parallel to the ramp, therefore:
where s = 18 m is the displacement.
Therefore the average power needed is:
b)
The instantaneous power at any point of the motion is given by
where
is the force applied
v is the velocity of the object
We already calculated the applied force:
While since this is a uniformly accelerated motion, we can find the velocity at the end of the 3.0 seconds using the suvat equation:
And therefore, the instantaeous power at 3.0 sec is:
Learn more about power:
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Four electrons are placed at the corner of a square
So we will first find the electrostatic potential at the center of the square
So here it is given as
here
r = distance of corner of the square from it center
now the net potential is given as
now potential energy of alpha particle at this position
Now at the mid point of one of the side
Electrostatic potential is given as
here we know that
now potential is given as
now final potential energy is given as
Now work done in this process is given as