21. light changes its direction when travelling through a new medium because denser mediums have a higher angle of refraction.
Explanation:
1. Convex mirror is curved outward.
2. Convex mirror forms an image that is smaller than the object.
3. Concave mirror is used to focus light rays. That's why it is also known as a converging mirror.
4. Plane mirror has a flat surface. It forms the same size of the image as that of the object.
Answer:
240m/s
Explanation:
The equation to calculate is wavelength= velocity/ frequency so to find the velocity you would have to multiply frequency by wavelength.
B. truthfully it's the only one that makes sense
Centripetal force is equal to (mv^2)/r
The way I use to answer these question is to set every variable to 1
m=1
v=1
r=1
so centripetal force =1
then change the variable we're looking at
and since we're find when it's half we could either change it to 1/2 or 2, but 2 is easier to use
m=1
v=2
r=1
((1)×(2)^2)/1=4
So the velocity in the 1st part is half the velocity in the 2nd part and the centripetal force is 4× less
The answer is the centripetal force is 1/4 as big the second time around
