The intensity of the waves from a point source at a distance d from the source is i. at what distance from the sources is the intensity equal to 2i

Explanation:

Intensity of the waves from a point source can be given by Power divided by surface area.

For P Power source and at a distance d from source Intensity is given by

when intensity is 2I then it is at a distance of let say d'

Divide 1 and 2 we get

explanation:

as the height from which the ruler was dropped increased, the speed of the ruler at ryan's hand increased.

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.