Answer: stratosphere
The stratosphere is the second to last layer of atmosphere to the Earth. It is about 40,000 feet above, and this is the range where planes fly. So, the answer is stratosphere.
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Answer:

Explanation:
Given that,
The work function for silver is 4.73 eV.
We need to find the value of the work function from electron volts to joules.
We know that,

For 4.73 eV,

So, the work function for silver is
.
having to push a rough and heavy box across the floor to move it
Explanation:
Friction is not a useful force because we have to exert even more force to push a body that is rough and heavy across the floor to move it.
- Frictional force is a force that opposes the motion of a body.
- It costs more and uses more energy to push a rough and heavy box on surface because of friction.
- This wastes energy in systems that deals with pushing.
Friction is useful in that:
- the heat energy produced when two surfaces rub together is very useful.
- the friction between your feet and the floor keeping you from slipping and makes walking possible.
- the tread on tires helping the moving vehicle slow down and stop when necessary.
learn more:
Friction brainly.com/question/7174363
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