Answer:
7.1 meters
Explanation:
We need to apply Newton's second law which explains the dynamics of objects under the effect of net forces.
The woman described in the question weighs 500N and has a speed of 4 m/s. If the net force acting on her was zero, she would continue to move at that speed forever (Newton's first law). But we know that there is friction and that force always goes against the movement. In the absence of a counterforce, the friction force is unbalanced and the woman will eventually stop.
The weight of the woman is
We can know her mass
We know that the friction force is
Where N is the normal force, which in this conditions is equal to the weight. So the net force is
It's negative because it's oppossed to the movement, assumed to the right side. Since
From the formulas of cinematics we know:
Solving for x when
Answer:
Mass of the sled in the snow 83.33 kg.
<u>Explanation</u>:
Given that,
Force applied to move the sled in the snow (F) = 75N
We know that
Newton's second law of motion is
F = ma (Or "force" is equal to "mass" times "acceleration".)
So if we move this around we can isolate mass and get mass
M = 83.33 kg
Mass of the sled in the snow <u>83.33 kg.</u>
Answer:
When there is a change in magnetic flux linkage through a loop of wire, an electromotive force is induced in the loop, according to the Faraday-Newmann-Lenz Law:
where
N is the number of turns in the loop
is the change in magnetic flux through the loop
is the time elapsed
The negative sign in the formula represents Lenz's Law, and tells us about the direction of the electromotive force.
In fact, the negative sign means that the direction of the induced emf is such that to oppose to the change in the magnetic flux that originated the induced emf.
This is a consequence of the law of conservation of energy: no energy can be created out of nowhere. In fact, when the emf is induced in the loop, electrical energy appears in the circuit; however, this electric energy cannot come out of nowhere. Instead, it is just "created" from the transformation of some other form of energy (for instance, the mechanical energy that is used to move the loop in the magnetic field, and changing its magnetic flux).
The negative sign in Lenz's Law tells exactly this: the direction of the induced emf is such that it opposes the initial change in magnetic flux that generated the induced emf, so that overall the total energy is conserved.