One of the contests at the school carnival is to throw a spear at an underwater target lying flat on the bottom of a pool. The water is 0.800 m deep. You're standing on a small stool that places your eyes 3.10 m above the bottom of the pool. As you look at the target, your gaze is 30∘ below horizontal. At what angle below horizontal should you throw the spear in order to hit the target?

The angle below horizontal you throw the spear in order to hit the target = 31 degree

Explanation: please find the attached files for the solution and figure

answer: 0.20

explanation: this can only be the answew because all the other measuremnets are not close

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.