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)
24. A, natural ph scale for it not to be acidic is 7-8
25. A, not sure about this one
26. A, looked it up
27. A, because it has to be shaken up to make the mixture appear and taste more combined.
28. D, i just guessed
29. D, that answer is stupid so it is the answer because it said not a property
30. A, looked it up
Answer:
If the force remains the same, the acceleration would decrease
Explanation:
According to Newton's second law, the acceleration of an object is given by

where
F is the force applied to the object
m is the mass of the object
As we see from the formula, the acceleration a is inversely proportional to the mass, m. Therefore, if the force F remains constant, this means that if the mass of the skateboarder increases, then the acceleration will decrease.
Answer:
v_f = 3 m/s
Explanation:
From work energy theorem;
W = K_f - K_i
Where;
K_f is final kinetic energy
K_i is initial kinetic energy
W is work done
K_f = ½mv_f²
K_i = ½mv_i²
Where v_f and v_i are final and initial velocities respectively
Thus;
W = ½mv_f² - ½mv_i²
We are given;
W = 150 J
m = 60 kg
v_i = 2 m/s
Thus;
150 = ½×60(v_f² - 2²)
150 = 30(v_f² - 4)
(v_f² - 4) = 150/30
(v_f² - 4) = 5
v_f² = 5 + 4
v_f² = 9
v_f = √9
v_f = 3 m/s