Explain how to identify a starting position on a line.

We can easily find out the beginning point of the line by using dot representation.

When it comes to position vector, it expresses the exact position of certain object from the starting point of  the coordinate system.  

The vector is a straight line that has a certain end  which is fixed to its body.  

The other end is linked with a moving point that tells an accurate position of that specific point.

answer; /// the above statement is (true);

answer: 802.3 kilo joules of energy represents 191.75 kilo calorie of energy.

explanation:

energy released during combustion of one mole methane = 802.3 kilo joules

if 1 kilo joule = 0.239006   kilo calorie

then ,802.3 kilo joule will be = 802.30.239006 kilo calorie

802.3 kilo joule = 191.75 kilo calorie

hence, the energy in kilo calorie is 191.75 kilo calorie.