1.ans:  No the tension in the string of a simple pendulum is not constant throughout the motion                                     

v is velocity of the bob and theta is the angle made by the string with vertical axis.

as v and θ both are variable T is also variable.

T is maximum at mean position as at mean position v is max and the angle is minimum.

2.ans: If the amplitude of the simple...

The difference between Gram atomic  mass and Gram atomic molecular are given below:

It is theoretically possible for a substance to have a negative value of cubical expansivity, which means that the substance would contract rather than expand when the temperature increases. However, it is very rare for a substance to have a negative value of cubical expansivity over a significant range of temperatures.

One example of a substance that has a negative value of cubical expansivity over a limited range of temperatures is water. Water has a positive value of cubical expansivity at...