Answer:
C. The net work done by the two forces is zero joules.
Explanation:
Work (W) is defined as the product of force F) by the distance (d)the body travels due to this force.
W= F*d Formula ( 1)
The work is positive (W+) if the force has the same direction of movement of the object.
The work is negative (W-) if the force has the opposite direction of the movement of the object.
The component of the force that performs work must be parallel to the displacement.
Calculation of the forces
We apply Newton's second law:
∑F = m*a
∑F : algebraic sum of the forces in Newton (N)
m : mass in kilograms (kg)
a : acceleration in meters over second square (m/s²)
∑F = m*a
a = 0 because the elevator moves at constant speed.
∑F=0
T-W = 0
T = W
Calculation of work done by the forces
W₁ : work done by the gravity= (+ W*d ) J
W₂ : work done by the tension force=( -T*d) J
Net work done by the two forces(W₁-W₂):
W₁= W₂ .because T = W
W₁-W₂ =0
Ohms law = v= Ir
V= 0.02 x 4000 = 80v
you can check attachment for answer.
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Answer:
A permanent magnet creates a magnetic field at all points in the surrounding region.
An electric current in a conductor creates a magnetic field at all points in the surrounding region.
A moving electric charge creates a magnetic field at all points in the surrounding region.
Explanation:
Magnet field is a region around the magnet in which the magnetic force can be experienced. A magnet has two poles: North pole and South pole. A Magnetic field originates from north pole and ends at south pole.
Magnets are of two types: Permanent magnet and temporary magnet.
A moving charge produces magnetic field. A stationary charge can not produce a magnetic field.
The rate of flowing charge constitutes an electric current. If the cardboard is placed around the current carrying conductor and the iron fillings spread around the cardboard then the iron nails get stick to it. It means that a current carrying conductor creates a magnetic field around it.
Therefore, the true statements from the given statements are as follows;
A permanent magnet creates a magnetic field at all points in the surrounding region.
An electric current in a conductor creates a magnetic field at all points in the surrounding region.
A moving electric charge creates a magnetic field at all points in the surrounding region.
In a surface wave (like water) the water goes up and down, but the wave travels across (parallel to) the surface.
