Answer:
Im gonna say it is answer A:) Hope this helps!
Explanation:
Answer:
a) variation of the energy is equal to the work of the friction force
b) W = Em_{f} -Em₀
, c) he conservation of mechanical energy
Explanation:
a) In an analysis of this problem we can use the energy law, where at the moment the mechanical energy is started it is totally potential, and at the lowest point it is totally kinetic, we can suppose two possibilities, that the friction is zero and therefore by equalizing the energy we set the velocity at the lowest point.
Another case is if the friction is different from zero and in this case the variation of the energy is equal to the work of the friction force, in value it will be lower than in the calculations.
b) the calluses that he would use are to hinder the worker's friction force and energy
W = Em_{f} -Em₀
N d = ½ m v² - m g (y₂-y₁)
y₂-y₁ = 35 -10 = 25m
c) if there is no friction, the physical principle is the conservation of mechanical energy
If there is friction, the principle is that the non-conservative work is equal to the variation of the energy
you could use one of your scientific experiments you did over the past few years.
You could make an solinoid.
Hope this helps! Lol
Answer:
B.0 N
Explanation:
Based on the description of the free-body diagram, there are only two forces acting on the child sitting on the seat:
- The force of gravity, Fg=-100 N, in the downward direction
- The normal reaction of the chair on the child, Fn=100 N, in the upward direction
The two forces have same magnitude but in opposite directions, so the net force (resultant of the two forces) is zero:
