Answer:
f = 2 Hz
Explanation:
The frequency of a wave is defined as the no. of waves passing per unit of time. Therefore, the frequency of a wave can be calculated by the following formula:
where,
f = frequency of the wave = ?
t = time passed = 1 s
n = no. of waves passing in time t = 2
Therefore,
<u>f = 2 Hz</u>
Using Ampere's Law, the magnetic field produced inside this solenoid is given by
B = uo N I / h
where uo is the vacuum permeability, N is the number of turns in the solenoid and h is the length of the solenoid. Earth's magnetic field is around 50 microteslas in North America thus the current needed in the solenoid is
I = B h / (uo N) = (50 E-6 ) (4) / ((4 pi E-7)(6000) ) = 0.026 A
I = 26 mA
So you need a current of around 26 mA.
Answer:
Explanation:
Given:
- mass of solid disk,
- radius of disk,
- force of push applied to disk,
- distance of application of force from the center,
<em>For the condition of no slip the force of static friction must be greater than the applied force so that there is no skidding between the contact surfaces at the contact point.</em>
where:
= static frictional force
With the given values of , we have
Try dealing with the powers of 10 first: On the right, we have
Meanwhile, the other values on the right reduce to
Then taking units into account, we end up with the equation
Now we solve for :
or, if taking significant digits into account,