(a) No, because the mechanical energy is not conserved
Explanation:
The work-energy theorem states that the work done by the engine on the airplane is equal to the gain in kinetic energy of the plane:
(1)
However, this theorem is only valid if there are no non-conservative forces acting on the plane. However, in this case there is air resistance acting on the plane: this means that the work-energy theorem is no longer valid, because the mechanical energy is not conserved.
Therefore, eq. (1) can be rewritten as
which means that the work done by the engine (W) is used partially to increase the kinetic energy of the airplane (
) and part is lost because of the air resistance (
).
(b) 77.8 m/s
First of all, we need to calculate the net force acting on the plane, which is equal to the difference between the thrust force and the air resistance:
Now we can calculate the acceleration of the plane, by using Newton's second law:
where m is the mass of the plane.
Finally, we can calculate the final speed of the plane by using the equation:
where
is the final velocity
is the initial velocity
is the acceleration
is the distance travelled
Solving for v, we find
1. When the object is waiting to be released, it is storing a lot of potential energy. When it is released, the potential energy that was once stored is converted into kinetic energy.
Answer:
A) coil A
Explanation:
According to Faraday, Induced emf is given as;
E.M.F = ΔФ/t
ΔФ = BACosθ
where;
ΔФ is change in magnetic flux
θ is the angle between the magnetic field, B, and the normal to the loop of area A
A is the area of the loop
B is the magnetic field
From the equation above, induced emf depends on the strength of the magnetic field.
Both coils have the same area and are oriented at right angles to the field.
Coil A has a magnetic field strength of 10-T which is greater than 1 T of coil B, thus, coil A will have a greater emf induced in it.
The AREA of the shaded region is the moving object's displacement.
<span>Electromagnetic waves differ fundamentally from either water or sound waves because they does not require any medium, they can travel in free space (vacuum)
Hope this helps!</span>
