An electric fence displays a warning sign about the voltage and amperage of the fence. How would amperage and voltage affect the
1 answer:
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Answer:
Explanation:
First of all, let's find the cross-sectional area of the copper wire. The radius of the wire half the diameter:
So the area is
Now we can calculate the resistance of the piece of copper wire between the bird's feet, with the formula:
where
is the resistivity of copper
is the length of the piece of wire
is the cross-sectional area
Substituting, we find
And since we know the current in the wire, I=149 A, we can now find the potential difference across the body of the bird, by using Ohm's law:
The definition of mechanical energy allows to find the results for the questions about the energy changes in the movement of the system are:
1) The midpoint of the path. Em = 784 J
2) Lowest point of the trajectory Em = 784 J
3) Acceleration of gravity is: g = 9.8 m/s²
4) The bowling ball has more kinetic energy as its height decreases.
<h3>Mechanical energy.</h3>Mechanical energy is the sum of the kinetic energy due to motion and the potential energies of the body. In the case of no friction the energy remains constant at all points, this is one of the most important principles of physics.
Em = K + U
Em = ½ m v² + m g h
Where Em is the mechanical energy, K and U the kinetic and potential energy, respectively, m the mass, v the velocity. G the acerleacion of gravity and h the height where the body is.
In this case when the ball is on top of the building of height y = 40 m, all its energy is potential.
Em = U = m g h
Em = 2 9.8 40
Em = 784 J
when the body falls it begins to acquire speed, therefore its kinetic energy increases and the height decreases, therefore its potential energy decreases, but the sum of the two remains constant.
1) Let's calculate the energy at the midpoint of the path.
They indicate that the speed is v= 19.8 m/s and the height is y2 = 20m
Em = ½ m v² + m g h
em = ½ 2 19.8 ² + 2 9.8 20
em = 392 + 392
Em = 784 J
We see that the kinetic and potential energy have the same value and the mechanical energy maintains its initial value.
2) We calculate the energy at the lowest point of the trajectory.
They indicate that the speed is v= 28 m/s and = height is zero h=0
Let's calculate
Em = ½ m v² + m g h
Em = ½ 2 28² + 0
Em = 784 J
At this point, all energy is kinetic and mechanical energy is conserved.
3) The acceleration of gravity comes from Newton's second law where the force is the universal attraction.
F =
F= ma
In the case of a body near thesurfacee of the distance of the radius of the planet and the acceleration is called gravity
g = a =
g =
g = 9.81 m/s²
4) The bowling ball has more kinetic energy as its height decreases, at the point where the height is half the kinetic and potential energy are equal.
In conclusion using the definition of mechanical energy we can find the results for the questions about the energy changes in the movement of the system are:
1) The midpoint of the path. Em = 784 J
2) Lowest point of the trajectory Em = 784 J
3) Acceleration of gravity is: g = 9.8 m/s²
4) The bowling ball has more kinetic energy as its height decreases.
Learn more about mechanical energy here: brainly.com/question/24443465
Answer:
(A) 0.001 m
(B) 0.75 m/s
(C)
Explanation:
distance (d) = 2 mm
frequency (f) = 120 Hz
(A) amplitude (A) = half the distance moved by the blade
amplitude = 2 / 2 = 1 mm = 0.001 m
(B) maximum blade speed (v) = ωA = 2πfA
v = 2 x 3.14 x 120 x 0.001 = 0.75 m/s
(c) maximum blade acceleration (a) =
a = =