<span>A moving electrical charge produces a magnetic field and a moving magnetic field produces an electrical field. An electromagnet works by coiling a bunch of wire and spinning a couple of magnets around that wire at high speeds. When this occurs the magnets induce an electric current in the wire and hence the electricity production. Once the magnets stop spinning, the induced electrical field dissipates and the current stops flowing through the wire.
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Answer:
(a) Magnitude of static friction force is 109 N
(b) Minimum possible value of static friction is 0.356
Solution:
As per the question;
Horizontal force exerted by the girl, F = 109 N
Mass of the crate, m = 31.2 kg
Now,
(a) To calculate the magnitude of static friction force:
Since, the crate is at rest, the forces on the crate are balanced and thus the horizontal force is equal to the frictional force, f:
F = f = 109 N
(b) The maximum possible force of friction between the floor and the crate is given by:

where
N = Normal reaction = mg
Thus

For the crate to remain at rest, The force exerted on the crate must be less than or equal to the maximum force of friction.




Answer:
The magnetic field of Earth is created by currents of electricity that flow in the molten center.
Explanation:
Answer:
The correct answer is - oxygen.
Explanation:
Cardiovascular endurance is the ability to do physical activity or exercise without affecting or being tired for a longer time period. Aerobic exercise or activity can help to increase cardiovascular endurance.
Improving the cardiovascular system helps in delivering oxygen as per the demands with the help of the heart that pumps the oxygen-rich blood to different organs of an individual and lungs by inhaling enough oxygen.