Answer:
Explanation:
Yes she is doing work. With or without the groceries, she is still doing work. She does more work with the groceries than without because Work is defined by F which is defined by mass. The mass increases with the groceries.
The work done is against the force of gravity.
I know that its not the second law. I'm almost positive its the first one. Please let me know if I'm wrong. This sentence makes no sense when you put it with the third law. So, the first law is my guess...
Newton's second law - the law of acceleration (acceleration = force/mass). Newton's second law states that the acceleration of an object is directly related to the net force and inversely related to its mass. Acceleration of an object depends on two things, force and mass.
The ramp does 480J of useful work with an efficiency of 80% .
<h3>What is efficiency of work done ?</h3>
- Efficiency is the ratio of the useful energy released by a system to the input energy .
- Mathematically, efficiency of energy = out put energy/ input energy
<h3>
What is the useful work done by the ramp having efficiency 80% and an input work done 600J?</h3>
- The efficiency =output work done/ input work done
- 80% =output work done/ 600J
- output work done =( 80×600)/100
=480J
Thus, we can conclude that the useful work done by the ramp is 480J.
Learn more about efficiency of energy here:
brainly.com/question/14280607
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