Question

the coefficient of cubical expansion of a substance depends on?
change in volume
original volume
rise in temperature
none of the above

the magnitude of the resultant vector of the vectors 2i+2j-k and j+7k is
0
5
7
10

Answer 1

The coefficient of cubical expansion, is a property of the material and is usually taken as a constant. The relation is:
\[\Delta V=\beta V \Delta T\] Where B is the coefficient of cubical expansion.

2i+2j-k + j + 7k = 2i+3j+6k
Use Pythagoras theorem to get the magnitude of the resultant vector: \[\sqrt{2^{2}+3^{2}+6^{2}}=7\]