Physics fail

If sound is increased in intensity by a factor of 100,000, what is the change in decibels? I thought 50? other options are 5, 500, and 100,000. Please explain because I'm confused on how this works.

When the pendulum bob reaches the mean position, the net force acting on it is zero. Why then does it swing past the mean position? I have no idea.. i know that it has momentum ..but...

Four resistors each of resistance 4 Ù are connected to form a square loop. What is the equivalent resistance between two points on its diagonal AC or BD? A-------------D | | B-------------C That's what it looks like on my homework. Thank you in advance

How does current change for resistors in series? What is the equivalent resistance for resistors in series?

An electron experiences 1.2 x 10^-3 force when it enters the external magnetic field, B with a velocity v. What is the force experienced by the electron if the magnetic field is increased two times and the velocity is decreased to half? Okay so I know the...

What is the formula for the force experienced by a moving charge q whose velocity v forms an angle è with a magnetic field B?

Current flow through a lamp is 1.3 A. How many Coulombs of charge are passed through the lamp in 2 minutes? Formula for coulombs and current? Not sure..

Thanks very much guys!!

Doesn't that mean it's at rest? I thought it had something to do with gravity pulling on the object? Because the bob is still moving so technically it's not at rest right?

Thanks so much Elena

also, what is the formula for magnetic flux? Thank you for your help