Answer:
Explanation:
From the question we are told that
The moment of inertia is 
The final angular speed is 
The time taken is 
The initial angular speed is 
Generally the average angular acceleration is mathematically represented as
=> 
=> 
Generally the torque is mathematically represented as
=> 
=> 
Answer:
The formula comes from Lorentz force law which includes both the electric and magnetic field. If the electric field is zero, the force law for just the magnetic field is <u>F=q(ν×B</u>) . Here, F is force and is a vector because the force acts in a direction. q is the charge of the particle. v is velocity and is a vector because the particle is moving in some direction. B is the magnetic flux density.
We can derive an expression for the magnetic force on a current by taking a sum of the magnetic forces on individual charges. (The forces add because they are in the same direction.) The force on an individual charge moving at the drift velocity vd. Since the magnitude of B is constant at every line element of the loop (circle) and it dot product with the line element is B dl everywhere, therefore
∮B dl=μ0 I
B ∮dl=μ0 I
B 2πr=μ0 I
B=μ02πr Id=μ0/4π I dl×rr3
Since, r can be written as r=(rcosθ,rsinθ,z) and dl as dl=(dl,0,0) And now, if we take the cross product we would get
dl×r=−z dlj^+rsinθk^
and therefore the magnitude of dB is equal to
dB=μ0/4π I |dl×r|/r3=μ0/4π I z2+r2sin2θ−−−−−−−−−−√dl/r3
Thus, magnetic field is depending on r,θ,z.
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Answer:
A
Explanation:
Iron and gadlinium are both very easily made into magnetic substances. Cobalt is also capable of being magnetized. Aluminum, put in an alloy, can make a magnetic substance, but
Aluminum by itself is not able to be magnetized.
An example is when u rub your pen on your hair hard that is friction
It is salt water because they are two things combined together.
