Answer:
The near point of an eye with power of +2 dopters, u' = - 50 cm
Given:
Power of a contact lens, P = +2.0 diopters
Solution:
To calculate the near point, we need to find the focal length of the lens which is given by:
Power, P = 
where
f = focal length
Thus
f = 
f =
= + 0.5 m
The near point of the eye is the point distant such that the image formed at this point can be seen clearly by the eye.
Now, by using lens maker formula:

where
u = object distance = 25 cm = 0.25 m = near point of a normal eye
u' = image distance
Now,



Solving the above eqn, we get:
u' = - 0.5 m = - 50 cm
Answer:
Symptoms of excessive stress include all of the following EXCEPT: increased energy level.
Answer:
B. the force of friction of the road on the tires
Explanation:
Unless the car engine is like jet engine, the main force that accelerates the car forward is the force of friction of the road on the tires, which is ultimately driven by the force of engine on the tires shaft. As the engine, and the shaft are part of the system, their interaction is internal. According to Newton laws of motion, the acceleration needs external force, in this case it's the friction of the road on the tires.
Answer:
The marble will start to decrease in speed
Explanation:
The longer the table is the more the marbles speed would decrease because marbles can only be fast for a certain amount of time
Answer:
Approximately 1.62 × 10⁻⁴ V.
Explanation:
The average EMF in the coil is equal to
,
Why does this formula work?
By Faraday's Law of Induction, the EMF
induced in a coil (one loop) is equal to the rate of change in the magnetic flux
through the coil.
.
Finding the average EMF in the coil is similar to finding the average velocity.
.
However, by the Fundamental Theorem of Calculus, integration reverts the action of differentiation. That is:
.
Hence the equation
.
Note that information about the constant term in the original function will be lost. However, since this integral is a definite one, the constant term in
won't matter.
Apply this formula to this question. Note that
, the magnetic flux through the coil, can be calculated with the equation
.
For this question,
is the strength of the magnetic field.
is the area of the coil.
is the number of loops in the coil.
is the angle between the field lines and the coil. - At
, the field lines are parallel to the coil,
. - At
, the field lines are perpendicular to the coil,
.
Initial flux:
.
Final flux:
.
Average EMF, which is the same as the average rate of change in flux:
.