The mechanical advantage of any machine is: a) the efficiency of the machine b) the work done by the machine c) the ratio of the work done by the machine to the work expended on it d) the ratio of the force exerted by the machine to the force applied to e) the ratio of the force applied to the machine to the force exerted by it it

Option D) the ratio of the force exerted by the machine to the force applied

Explanation:

The measure of the amplification of the force applied to a mechanical device or a measure of the force exerted by a mechanical device.

The input of the tool or machine is then conserved and the forces are trade off against motion to achieve a required level of amplification.

Therefore, only option c. complies with it.

a high pressure system is a dense air mass that is usually cooler and drier than the surrounding air. a low pressure system is a less dense air mass that is usually wetter and warmer than the surrounding air.

in general, areas that experience high atmospheric pressure also experience fair weather. low pressure systems can cause the formation of clouds and storms. air usually flows from areas of high pressure to areas of low pressure..

the box does not move because you need to use a force greater than 300 n. you are only using 50 n. it needs to at least be 301 n for the box to move because then it is an unbalanced force and it will move the way that the greater force is pushing it. if you use only 300 n it will be a balanced force and will not move because the force you are exerting on the   box is the same as its force.

hope this !

im sorry if i went too in depth, i am going to include a link to a video on khan academy that will explain this.   hope that you like the video and that it explains more in detail to you.

that is the link.