Aball is thrown straight up into the air. at each of the following instants, is the ball's acceleration ay equal to g, −g, 0, g?

Just after leaving your hand: -g

At the very top: g

Just before hitting the ground: g

Explanation:

A ball is thrown straight up into the air. At each of the following instants, is the ball's acceleration ay equal to g, -g, 0, < g, or > g? a. Just after leaving your hand? b. At the very top (maximum height)? c. Just before hitting the ground?

Remember that in physics when you use gravity as the acceleration fo an object it is negative when the object has a positive velocity or towards the sky and away form the center of the earth and gravity is positive when the objet is falling or going towards the center of the earth, acceleration can´t be 0 when we are talinkg about gravity.

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.