The resistance of a conductor is given by
where L is the length of the wire,
the resistivity of the material and A the cross-sectional area.
We can see that if all the other quantities do not change, if the new length of the conductor is 4 times the original length:
, then the new resistance is also 4 times the original value:
Answer:
The length of the wire is 83.2 m.
Explanation:
Given that,
Power of heater, P = 300 W
Voltage, V = 110 V
The resistivity of nichrome wire is, 
The electric power of a wire is given by :
Area of cross section of the wire is :
Resistance of a material is given by :
So, the length of the wire is 83.2 m. Hence, this is the required solution.
Answer:
a) T² = (
) r³
b) veloicity the dependency is the inverse of the root of the distance
kinetic energy depends on the inverse of the distance
potential energy dependency is the inverse of distance
angular momentum depends directly on the root of the distance
Explanation:
1) for this exercise we will use Newton's second law
F = ma
in this case the acceleration is centripetal
a = v² / r
the linear and angular variable are related
v = w r
we substitute
a = w² r
force is the universal force of attraction
F = 
we substitute
w² = 
angular velocity is related to frequency and period
w = 2π f = 2π / T
we substitute
the final equation is
T² = () r³
b) the speed of the orbit can be found
v = w r
v = 
v = 
in this case the dependency is the inverse of the root of the distance
Kinetic energy
K = ½ M v²
K = ½ M GM / r
K = ½ GM² 1 / r
the kinetic energy depends on the inverse of the distance
Potential energy
U =
U = -G mM / r
dependency is the inverse of distance
Angular momentum
L = r x p
for a circular orbit
L = r p = r Mv
L =
L =
The angular momentum depends directly on the root of the distance
Answer:
one billion to ten billion joules.
Explanation:
To keep a 100-watt light bulb going for one second, one hundred joules of energy will be used.
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