Answer:
A is a solid. C is a gas. In solid an liquid the particals are touching. In C, the particals have less affect on each other because they are so far apart.
Answer:
B) waves speed up
C) waves bend away from the normal
Explanation:
The index of refraction of a material is the ratio between the speed of light in a vacuum and the speed of light in that medium:
where
c is the speed of light in a vacuum
v is the speed of light in the medium
We can re-arrange this equation as:
So from this we already see that if the index of refraction is lower, the speed of light in the medium will be higher, so one correct option is
B) waves speed up
Moreover, when light enters a medium bends according to Snell's Law:
where
are the index of refraction of the 1st and 2nd medium
are the angles made by the incident ray and refracted ray with the normal to the interface
We can rewrite the equation as
So we see that if the index of refraction of the second medium is lower (
), then the ratio 
is larger than 1, so the angle of refraction is larger than the angle of incidence:
This means that the wave will bend away from the normal. So the other correct option is
C) waves bend away from the normal
Newton's 2nd law of motion:
Force = (mass) x (acceleration)
= (0.314 kg) x (164 m/s²)
= 51.5 newtons
(about 11.6 pounds) .
Notice that the ball is only accelerating while it's in contact with the racket.
The instant the ball loses contact with the racket, it stops accelerating, and
sails off in a straight line at whatever speed it had when it left the strings.
Answer:
Explanation:
I ASSUME you mean acceleration is 3 m/s²
v² = u² + 2as
s = (v² - u²) / 2a
s = (18² - 12²) / (2(3))
s = 30 m
to verify we can see that the acceleration time is
t = (18 - 12) / 3 = 2 s
s = 0 + 12(2) + ½(3)2² = 30 m
