A high-jumper, having just cleared the bar, lands on an air mattress and comes to rest. Had she landed directly on the hard grou
1 answer:
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Answer:
electric potential, V = -q(a²- b²)/8π∈₀r³
Explanation:
Question (in proper order)
Consider two thin coaxial, coplanar, uniformly charged rings with radii a and b (b < a) and charges q and -q, respectively. Determine the potential at large distances from the rings
<em>consider the attached diagram below</em>
the electric potential at point p, distance r from the center of the outer charged ring with radius a is as given below
Va = q/4π∈₀ [1/(a² + b²)¹/²]
Also
the electric potential at point p, distance r from the center of the inner charged ring with radius b is
Sum of the potential at point p is
V = Va + Vb
that is
the expression below can be written as the equivalent
likewise,
hence,
1/r is common to both equation
hence, we have it out and joined to the 4π∈₀ denominator that is outside
by reciprocal rule
1/a² = a⁻²
by binomial expansion of fractional powers
where
if we expand the expression we have the equivalent as shown
also,
the above equation becomes
Answer
OR
Answer:
225 rpm
Explanation:
The angular acceleration of the fan is given by:
where
is the final angular speed
is the initial angular speed
is the time interval
For the fan in this problem,
Substituting,
Now we can find the angular speed of the fan at the end of the 5th second, so after t = 5 s. It is given by:
where
Substituting,