a motor pulls up a block suspended on a string, so that the tension in the string is equal to the qeight force on the block. the
1 answer:
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Answer:
a) 0.142mH
b) 14mV
Explanation:
the complete answer is:
(a) Calculate the self-inductance of a solenoid that is <ghtly wound with wire of diameter 0.10 cm, has a cross-sec<onal area of 0.90 cm2 , and is 40 cm long. (b) If the current through the solenoid decreases uniformly from 10 to 0 A in 0.10 s, what is the emf induced between the ends of the solenoid
a) the self inductance of a solenoid is given by:
μo: magnetic permeability of vacuum = 4\pi*10^{-7}N/A^2
A: cross sectional area = 0.9cm^2=9*10^{-5}m
L: length of the solenoid = 40cm = 0.4m
The N turns of the wire is calculated by using the diameter of the wire:
N = (40cm)/(0.10cm)=400
By replacing in the formula you obtain:
the self inductance is 1.42*10^{-4}H = 0.142mH
b) to find the emf you can use:
the emf induced is 14mV
Answer:
Towards the center of the circle
Explanation:
When an object is moving in uniform circular motion, it means that it is moving at a constant speed in a circular path.
In order to follows a circular path, the particle must have a net force acting on it, that it makes it constantly changing direction - and therefore, causing an acceleration - and this force is called centripetal force.
The direction of this centripetal force is always towards the centre of the circular path.
The nature of the centripetal force is always different, depending on the situation. For instance: for a satellite orbiting the Earth in circular motion, the centripetal force is provided by the force of gravity. For a car moving round a curve, the centripetal force is provided by the force of friction between the tyres and the road.
The magnitude of the centripetal force is given by
where
m is the mass of the object
v is its speed
r is the radius of the circle