Answer:
P = 4.5 watts
Explanation:
Given that,
EMF of the circuit, E = 3 volt
The resistance of the resistors, R = 2 ohms
We need to find the power of this circuit. The relation between power, emf and resistance is given by the formula as follows :
Substitute all the values,
So, the power of this circuit is equal to 4.5 watts.
Answer:
Current, I = 1000 A
Explanation:
It is given that,
Length of the copper wire, l = 7300 m
Resistance of copper line, R = 10 ohms
Magnetic field, B = 0.1 T
Resistivity,
We need to find the current flowing the copper wire. Firstly, we need to find the radius of he power line using physical dimensions as :
r = 0.00199 m
or
The magnetic field on a current carrying wire is given by :
I = 1000 A
So, the current of 1000 A is flowing through the copper wire. Hence, this is the required solution.
Answer:
The energy that the truck lose to air resistance per hour is 87.47MJ
Explanation:
To solve this exercise it is necessary to compile the concepts of kinetic energy because of the drag force given in aerodynamic bodies. According to the theory we know that the drag force is defined by
Our values are:
Replacing,
We need calculate now the energy lost through a time T, then,
But we know that d is equal to
Where
v is the velocity and t the time. However the time is given in seconds but for this problem we need the time in hours, so,
(per hour)
Therefore the energy that the truck lose to air resistance per hour is 87.47MJ
