If I remember correctly (from my studies long time ago) the layers are from the outer to the center:
SiAl : Silicon-Aluminum
SiMa : Silicon-Magnesium (although should be Mg)
NiFe : Nickel-Iron
The SiMa layer should have the lightest elements (Magnesium is lighter than Aluminum)
Answer:
Option A
Explanation:
From the question we are told that:
Mass 
Velocity 
Generally the equation for momentum for Ball A is mathematically given by
Initial Momentum



Final Momentum

Therefore

Generally the equation for momentum for Ball B is mathematically given by
Initial Momentum



Final Momentum

Therefore

Option A
Answer:
Velocity(v) = frequency(f) × wavelength
f = 0.3165
Wavelength = 2×length(L)
L = 157cm
Convert the length in centimetres to metre = 1.57m
v = 2×1.57 × 0.3165
v = 0.99m/s
Approx. 1m/s
Explanation:
The velocity of a wave is the product of its frequency and it's wavelength. The frequency is already known. The wavelength is the distance between two successive wave crests which is formed by sloshing water back and forth in the bath tub. Sloshing water to one end of the tub will produce a wave crest first at that end then the other completing a cycle. The wavelength will be twice the length of the bath tub as it is the distance that both crests are formed.
Wave crest is the highest point of a wave, and in this case is where the water rises to a high point in the bath tub
Protons, electrons, and neutrons. The nucleus (center) of the atom contains the protons (positively charged) and the neutrons (no charge).