Answer:
>400N is needed to balance that lever
Pet rocks contain organic matter
A boiling pot of water (the water travels in a current throughout the pot), a hot air balloon (hot air rises, making the balloon rise) , and cup of a steaming, hot liquid (hot air rises, creating steam) are all situations where convection occurs.
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Answer: having to push a rough and heavy box across the floor to move it
Explanation:
The Friction force is any force that is in opposite direction of the motion of an object or fluid due to the contact of this object or fluid with other bodies.
In this sense, there are different types of friction force thath are useful in different situations:
-The <u>Static friction force</u> prevents surfaces from slipping across each other. For example, the friction between your feet and the floor keeping you from slipping.
-The <u>kinetic friction force</u> as the force that helps the tires in a moving vehicle to slow down and stop when necessary.
However, if you want to push a heavy box across the floor to move it, the friction force will not be useful at all.