Exothermich cools and endo heats so it heats
A black hole is a cosmological object that is created when a massive star comes to the end of its life and collapses under its own gravity. Black holes have massive gravitational fields that even light cannot escape beyond a certain distance. Before being engulfed, matter that is pulled into a black hole should become very hot and emit electromagnetic radiation.
Answer:
At light intensity I = 3, is P a maximum
Explanation:
Given:

now differentiating the above equation with respect to Intensity 'I' we get

or

or

or

Now for the maxima 
thus,

or

or

or

or
I = 3
thus, <u>for the value of intensity I = 3, the P is maximum</u>
at I = 3

or

or

Answer:
friction reduces the efficiency of machines, thus we must reduce the friction force that is acting upon it.
The answer of <span> the change in electric potential difference is</span> -1.0 × 10^7 V. It is defined as the work done per unit charge. A potential difference of 1 V means that 1 joule of work is done per coulomb of charge or 1 V = 1 J C-1.