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:
Option D
490 J
Explanation:
When at a height of 100 am above and released, the ball initially posses only potential energy. When it falls, some potential energy is converted to kinetic energy.
Initial potential energy= mgh where m is the mass, g is the acceleration due to gravity and h is height. Substituting 1 Kg for m, 9.81 for g and 100 m for h then
PE initial = 1*9.81*100= 981 J
At 50 m, PE will be 1*9.81*50=490.5 J
Subtracting PE at 50 m from initial PE we get the energy that has been converted to kinetic energy hence
981-490.5= 490.5 J
Approximately, 490 J
The independent variable refers to the type of socks (synthetic socks), the dependent variable is the number of blisters and the control is the two weeks that she switches back to the cotton socks.
<h3>What is the dependent variable?</h3>
In an experiment, the dependent variable is those being tested and changes according to the independent variable.
The control group is the set of experimental conditions that is used to compare a given outcome in an experiment.
In conclusion, The independent variable refers to the type of socks (synthetic socks), the dependent variable is the number of blisters and the control is the two weeks that she switches back to the cotton socks.
Learn more about the dependent variable here:
brainly.com/question/25223322
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The correct options are:
1 How tall are you?
2How far is it from your house to your school?
3How wide is your refrigerator?
All these measurements involve to measure a length. Instead, the other two options involve to measure different physical quantities; for instance, the question
4 How much does your sister weigh?
Involve to measure a weight (and so, a mass), while the question
5 How warm is it in San Diego?
requires to measure a temperature.
