Light that enters the new medium <em>perpendicular to the surface</em> keeps sailing straight through the new medium unrefracted (in the same direction).
Perpendicular to the surface is the "normal" to the surface. So the angle of incidence (angle between the laser and the normal) is zero, and the law of refraction (just like the law of reflection) predicts an angle of zero between the normal and the refracted (or the reflected) beam.
Moral of the story: If you want your laser to keep going in the same direction after it enters the water, or to bounce back in the same direction it came from when it hits the mirror, then shoot it <em>straight on</em> to the surface, perpendicular to it.
Answer: vector yes
Explanation:
Acceleration is a vector, and thus has a both a magnitude and direction. Acceleration can be caused by either a change in the magnitude or the direction of the velocity.
Answer:
1-In a uniform electric field, the field lines are straight, parallel, and uniformly spaced this statement is true.
2-Electric field lines near positive point charges radiate outward. this statement is also true.
3-The electric force acting on a point charge is proportional to the magnitude of the point charge. this statement is true as well.
Explanation:
the electric field created by a point charge is defined by E=KQ/r^2 where k is constant, q is magnitude of charge and r is the distance away from the point charge so the electric filed is distance dependent and can not be constant at all distances.
electric field lines near a negative point charge are directed radially inward because negative charge attracts the field and is not clockwise.
there is a relation between intensity of light beam and the magnitude of electric field.<span>I=(1/2)c<span>ϵo</span>n<span>E2</span>=P/π<span>r2</span></span>
<span><span>E2</span>=2P/c<span>ϵo</span>nπ<span>r2</span></span>
E= magnitude of electric field
n= refractive index of medium
<span><span>μo</span><span>ϵ0</span>=1/<span>c2
</span></span>energy= power*time
= P*(1m/speed of light)<span><span>energy=(P∗1m)/c</span></span>
A) Upward
In order to find the direction of the magnetic force on the wire, we can use the right-hand rule: the index finger, the middle finger and the thumb of the right hand must be placed all of them perpendicular to each other.
So we have:
- Index finger: direction of current in the wire (from west to east)
- Middle finger: direction of magnetic field (from south to north)
- Thumb: direction of the force --> so it will be upward
So, the force will point upward.
B) 
The magnitude of the force exerted by the magnetic field on the wire is given by
where
I = 1.50 A is the current in the wire
L = 2.20 m is the length of the wire
Substituting into the equation, we find
