A. <span>Standing is health-enhancing because it uses energy.
Because standing can burn a lot of calories.</span>
(a) The free body of all the forces include, frictional force, weight of the box acting perpendicular and another acting parallel to the plane.
(b) When the box is sliding down, the frictional force acts towards the right.
(c) When the box slides up, the direction of the frictional force changes, it acts towards the left.
<h3>
Free body diagram</h3>
The free body diagram of all the forces on the box is obtained by noting the upward force and downward forces on the box as shown below;
/ W2
Ф → Ff
↓W1
where;
- Ff is the frictional force resisting the down motion of the box
- W1 is the perpendicular component of the box weight = Wcos(33)
- W2 is the parallel component of the box weight = Wsin(33)
(b) When the box is sliding down, the frictional force acts towards the right.
(c) When the box slides up, the direction of the frictional force changes, it acts towards the left.
Learn more about free body diagram of inclined objects here: brainly.com/question/4176810
Answer:
Because of the formula 
Explanation:
In this problem we are describing two different processes:
- Nuclear fission occurs when a heavy, unstable nucleus breaks apart into two or more lighter nuclei
- Nuclear fusion occurs when two (or more) light nuclei fuse together producing a heavier nucleus
In both cases, the total mass of the final products is smaller than the total mass of the initial nuclei.
According to Einsten's formula, this mass difference has been converted into energy, as follows:
where:
E is the energy released in the reaction
is the mass defect, the difference between the final total mass and the initial total mass
is the speed of light
From the formula, we see that the factor 
is a very large number, therefore even if the mass defect is very small, nuclear fusion and nuclear fission release huge amounts of energy.
Explanation:
its either a or d however i say the best choice is d
Answer: 5billion years
Explanation: The sun produces energy through radioactive fusion reaction.
Nebula theory states that the gaseous particles of the Earth collapsed as a result of its own gravity which continuously lead to fusion reaction for the production of nuclear energy.
The Core of the Sun is that area up to 25% from the radius of the sun,here the pressure here range up to 250million atmosphere containing mainly hydrogen which gets converted in Helium molecule. The core is the center for energy production accounting for more than 98%, nuclear energy is transmitted at about 4.3million metric tons per second.
