' A ' is one crest of the wave. After every wavelength, there's another one.
' B ' . . . the vertical arrow under B shows the amplitude of the wave
' C ' is one trough of the wave. After every wavelength, there's another one.
' D ' . . . the horizontal arrow over D shows the wavelength.
I think it is D a light bulb
B. Deflate because volume is inversely proportional to temperature
The question is incomplete. The complete question is :
Consider a composite cube made of epoxy with fibers aligned along one axis of the cube (the fibers are parallel to four of the twelve cube edges). If the cube can only be loaded in axial tension such that the force is uniformly applied over - and is normal to - a cube face, what is the lowest possible positive length change the cube can experience under this tension? The applied tensile force is 102 KN. The unloaded cube edge length is 56 mm. The glass fibers have an elastic modulus of 200 GPa. The epoxy has an elastic modulus of 38 GPa. The cube is comprised of 18 vol% epoxy (the balancing vol % is glass fiber). Hint: The loading axis is intentionally unspecified. Answer Format: Lowest possible length increase (change of length) under tension.
Solution :
Given :
= 200 GPa

= 38 GPa

Edge length = 56 mm
Cube is loaded in axial tension such that the force is uniformly applied over a cube face.


GPa
Applied stress 

= 32.5 MPa
By Hooke's law



Length change, 

= 0.016 mm
Overview:
You would use a graduated cylinder to measure 25 ml of the liquid and use a scale to weigh the amount of Magnesium (it can be a balance but most labs now have small scales) and you would carefully put small amounts of magnesium until it states 2.5 grams.
Procedure:
Take the graduated cylinder and place it on the table. Carefully take the water and fill the graduated cylinder up to 25ml. If you took to much just simply pour some out and if you didnt take enough then put more. After you measured the water then you can pour the 25 ml of water into a beaker, but this is totally optional.
For the magnesium first you put on the scale and set it to grams. Afterwards just take small pieces of the magnesium and place it on the scale until you reach 2.5 grams. Afterwards you can carefully place the magnesium in another beaker or something like that.