Answer: (b)0.000012/k
Explanation:
The linear expansion of the metal rod is given by

where
is the linear expansion
is the initial length of the rod
is the linear expansivity
is the increase in temperature
By re-arranging the equation, we find the linear expansivity:

Answer:
A.B = -38
Explanation:
A = 2i + 9j and B = -i - 4j.
So, A.B = (2i + 9j).(-i - 4j)
= 2i.(-i) + 2i.(-4j) + 9j.(-i) + 9j.(-4j)
= -2i.i - 8i.j - 9j.i - 36j.j
since i.i = 1, j.j = 1, i.j = 0 and j.i = 0, we have
A.B = -2(1) - 8(0) - 9(0) - 36(1)
A.B = -2 - 0 - 0 - 36
A.B = -38
The correct answer is alpha
If he's falling in a straight line and his speed is not changing, that tells you that his acceleration is zero.
And THAT tells you that the forces on him are balanced, the net force acting on him is zero, and his motion is the same as it would be if there were NO force acting on him.
Actually its three way
Neutrons
Electrons
protons