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A river current has a velocity of 5 kmh relative to the shore. A boat moves in the same direction as the current at 4 kmh relative to the river. How do you calculate the velocity of the boat relative?
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What is the relationship between acceleraion and velocity?
Acceleration increases the velocity. There are two physics formulas that you can use to see more how they interact. The first is a formula for determining your current velocity at a given moment t, knowing your initial velocity and your current acceleration. v = v0 + at (v0 is v-naught. The zero is usually written as a subscript.) You can solve this equation for a to get a formula for acceleration as well. a = (v-v0)/t So, basically, at any given interval t, the acceleration has been added onto the current velocity that many times.
The direction of a magnetic field produced by an electric current depends on the direction of the what?
Flow of the current.
The what of an electromagnet is determined by the direction of current flow?
The electromagnet (polarity) is determined by the direction of current.
What is meant by thermal velocity of an electron?
It means that due to the temperature, electrons move back and forth randomly, even if there is no current. A current would imply a systematic movement of electrons, i.e., more electrons moving in one direction than in the other.
What current that does not reverse its direction of flow?
direct current
In direct current charges carries have a drift velocity but in alternating current there is no net velocity of the charge carriers. Explain why?
In direct current the charge carries always flow in the same direction, while in alternating current they change direction repeatedly, meaning overall there is no net direction.
A boat whose velocity through the water is 14 kmh is moving in a river whose current is 6 kmin relative to the riverbed The velocity of the boat relative to the riverbed must be between?
13.9 km hr
What is a downward flowing air current?
A current of air with its velocity directed downwards or in a direction below the horizontal. Mathematically v.n < 0 where v is the velocity vector and n is the upward normal at the surface.
What is the direction of the magnetic lines of force relative to the direction of electric current?
A: It is called rule of thumb using the right end grab a wire the thumb pointing on the current flow the fingers will point to the direction of flux
What is the relationship between acceleraion and velocity?
Acceleration increases the velocity. There are two physics formulas that you can use to see more how they interact. The first is a formula for determining your current velocity at a given moment t, knowing your initial velocity and your current acceleration. v = v0 + at (v0 is v-naught. The zero is usually written as a subscript.) You can solve this equation for a to get a formula for acceleration as well. a = (v-v0)/t So, basically, at any given interval t, the acceleration has been added onto the current velocity that many times.
Why direction of rotation is not reversed when both field and armature terminals are reversed?
The direction of the force that drives the machine is determined by the relative directions of the field and the armature current. By reversing the direction of both field and the armature current, the direction of the resulting force stays the same; you have to reverse the direction of one or the other; not both! Prove it for yourself, by applying Fleming's Left-Hand Rule (for conventional current flow); reverse the direction of both your first finger (field) and your second finger (armature current), and you thumb (direction of motion) will end up pointing in the same direction!
Why direction of rotation is not reversed when both field and armature terminal are reversed?
The direction of the force that drives the machine is determined by the relative directions of the field and the armature current. By reversing the direction of both field and the armature current, the direction of the resulting force stays the same; you have to reverse the direction of one or the other; not both! Prove it for yourself, by applying Fleming's Left-Hand Rule (for conventional current flow); reverse the direction of both your first finger (field) and your second finger (armature current), and you thumb (direction of motion) will end up pointing in the same direction!
What is the purpose of a commuter in a DC motor?
to make contact with the brushes and transfer the current to the appropiate windings in the armature.Another AnswerA commutator is a rotary reversing switch. It's function is to reverse the direction of the current through the rotor windings as they rotate, to ensure that the current direction around the windings remain in the same direction relative to the magnetic field, so that the torque always acts in the same direction.
What is the purpose of a commutator in a dc motor?
to make contact with the brushes and transfer the current to the appropiate windings in the armature.Another AnswerA commutator is a rotary reversing switch. It's function is to reverse the direction of the current through the rotor windings as they rotate, to ensure that the current direction around the windings remain in the same direction relative to the magnetic field, so that the torque always acts in the same direction.
If an electric current flows from negative to positive what happens when the current flow meets?
The current never really "meets" anywhere; It is at constant velocity in all parts of the circuit. Negative to positive is the direction it flows, nothing more.
When an electric current flows through a long conductor how does each free electron moves?
The individual electrons will move back and forth, as they do when there is no current. You would have to do very careful statistics to notice that there are slightly more electrons moving in one direction than in the other: the drift velocity (average velocity due to current) of the electrons is typically a fraction of a millimeter per second.
Why current density is vector quantity?
Current is not scalar. Current is a vector quantity. For simplicity, in electric circuits, current is scalar because the direction is assumed to be one way or another, rather than three dimensional.
