Answer:
Explanation:
1) As we know that work done is the product of force and the displacement of the point of action where force is applied
So here we have
[tex]W = 0[/tex]
as there is no displacement in the direction where the force is applied
2)As we know that work is product of force and displacement
So we will have
[tex]W_1 = 100 \times 4 = 400 J[/tex]
[tex]W_2 = 200 \times 1 = 200 J[/tex]
[tex]W_1 = 200 \times 1 = 200 J[/tex]
[tex]W_1 = 100 \times 3 = 300 J[/tex]
So maximum work is done on
A) Using a lever to lift 100 newtons up to 4 meters on to a shelf
3)
As we know that power is rate of work done
so we have
[tex]P = \frac{W}{t}[/tex]
[tex]P = \frac{420}{3}[/tex]
[tex]P = 140 W[/tex]
4)
As per energy conservation we know that
D) In a closed system, a system that isolated from its surrounds, the total energy of the system is conserved