Heat normally travels from areas of higher heat to areas of lower heat. For example, if you were to be in a classroom and all the windows and doors were closed, and then you opened a door, then the reason why the room becomes cooler is not because cold air comes inside the room. However, it is because when you open the door, the heat from the classroom you're in escapes the room. This is why it feels cooler when you open a door, or even a window. Heat is traveling from areas of higher heat to areas of lower heat.
I believe the answer is D
All it does is lets him pull in a more convenient direction to raise the load. It has no effect on the required force.
A vacuum is an electrical motor and<span> which it converts electrical energy into mechanical energy.
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