1 cubic cm is the same as 1 mL, so the answer would be C.
Answer A is incorrect
A crest is just one point. It is not the distance between 2 crests.
B is incorrect
A trough is just 1 point. It is not the distance between 2 troughs.
C is incorrect.
the amplitude measures the height of a crest from the middle of the wave to the crest (or trough).
D is the correct answer. That is the distance between 2 crests or 2 troughs
Answer:
0.010 m
Explanation:
So the equation for a pendulum period is: 
where L is the length of the pendulum. In this case I'll use the approximation of pi as 3.14, and g=9.8 m\s. So given that it oscillates once every 1.99 seconds. you have the equation:
Evaluate the multiplication in front
Divide both sides by 6.28
Square both sides
Multiply both sides by m/s^2 (the s^2 will cancel out)
Now now let's find the length when it's two seconds
Divide both sides by 6.28
Square both sides
Multiply both sides by 9.8 m/s^2 (s^2 will cancel out)
So to find the difference you simply subtract
0.984 - 0.994 = 0.010 m
