Answer:

Explanation:
After time "t" the angular position of A is given as

now we know that B start motion after time t1
so its angular position is also same as that of position of A after same time "t"
so we have

now since both positions are same




He identified triads of elements that had similar properties
Answer:
By 1000 joules
Explanation:
Given


Required
By how much does her GPA increases
To do this, we simply calculate the potential energy.

Where

At the ground level, the height is 0
i.e. 
So:

At:

So, we have:



Calculate the difference


<em>Hence, it increases by 1000 joules</em>