With respect to the ground, the 3 kg object has no or 0 potential energy, as one can compute the potential energy as Ep = mgh. Since the object is on the ground it posses no height and thus no potential energy.
Answer:
Gravity
Explanation:
When the ball is falling to the ground, there is only one force- gravity. In some cases, there may be air resistance, but that seems to be neglected here.
Normal force:
Cannot be included. Normal force is only applicable when object is on a surface, and it acts perpendicular to the surface. Since the ball is falling, there is no surface, and therefore no normal force. This question gives you unnecessary information, designed to trick you. Please remember when normal force is applicable.
Friction force:
Also only applicable when object is moving, and is on the table. Friction only applies when there is an applied force. There is no applied force when the ball is falling, so therefore no friction force.
Force of fall:
First of all, what is this? There is nothing called force of fall.
Gravity:
This is the only one that applies. Just draw a vector arrow from the bottom of the ball and label it mg (acceleration due to gravity).
A) the universe is expanding
Every galaxy is moving away from each other - not just us. And the further they are away, the faster they are moving
Heat of combustion.<span> The calorific value is the total energy released as heat when a substance undergoes complete combustion with oxygen under standard conditions. The chemical reaction is typically a hydrocarbon or other organic molecule reacting with oxygen to form carbon dioxide and water and release heat.</span>
For simplicity, let's call vector B-A vector C Then C is
Cx = (-6.1 - 2.2)
Cy = (-2.2 - (-6.9)) Or,
Cx = -8.3 Cy = 4.7
The magnitude is found with the Pythagorean theorem
||C|| = √(-8.3² + 4.7²) = 9.538
