Four red flags
The load being carried poses a hazard to vehicles in the proximity of the load-carrying vehicle, and so it is mandatory by law for the vehicle to make the load more visible. At night time, the load is marked using red lights, as flags would not be visible then.
Answer:
The magnitude of the net current = 18 A.
Direction of the net current is along the negative z axis.
Explanation:
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<u><em>Given:</em></u>
- Number of electrons flow through the given cross section,
- Number of electrons flow through the given cross section,
- Time interval for which the electrons and protons flow,
The current through a cross section is defined as the amount of charge passing through that cross section in unit time.
We know,
Charge on an electron,
Charge on a proton,
Therefore,
The amount of charge flowing due to electrons is given by
The amount of charge flowing due to protons is given by
The current flowing through the cross section because of the electrons is given as:
The negative sign shows that the current is due to the flow of negative charge, and the direction of current is always opposite to that of flow of negative charge i.e., electrons.
Thus, the direction of this current is along the negative z direction.
The magnitude of this current = 12 A.
The current flowing through the cross section because of the protons is given as:
The direction of this current is same as that of electrons,
The directions of the currents due to both, the electrons and the protons are along the negative z direction, therefore the magnitude of the net current is given as:
Efficiency of heat engine is determined by the ratio of difference in temperature of cold from hot reservoir to the temperature of hot reservoir over temperature of hot reservoir.
Answer:
Free-fall is defined as the movement where the only force acting on an object is the gravitational force.
By the second Newton's law, we have that:
F = m*a
Where F = Force, m = mass, a = acceleration.
We can write this as:
a = F/m
And the gravitational force can be written as:
F = (G*M/r^2)*m
Where G is the gravitational constant, M is the mass of the Earth in this case, and r is the distance between both objects (the center of the Earth and the free-falling object)
As the radius of the Earth is really big, the term inside the parentheses is almost constant in the region of interest, then we can write:
G*M/r^2 ≈ g
And the gravitational force is:
F = g*m
And by the second Newton's law we had:
a = F/m = (g*m)/m = g
a = g
Then the acceleration does not depend on the mass of the object.
Then the thing that is common among the free-falling objects is the vertical acceleration.