Ok, I may be completely off the mark here, but here's what I'm thinking: the period of a function is the shortest distance you have to travel along the x-axis for the function to begin another cycle (according to my lesson book). The cycle of a sine curve starts at zero and ends at 2pi, so the...
Homework Statement
The period of f is 5. If f(1)=4, f(2)=5, and f(4)=-2, the value of f(7) is:
Homework Equations
The standard format for trig functions is A\sinB(x-C)+D
A is the amplitude, \frac{2\pi}{B} is the period (for sin or cos functions), C is the phase, and D is the vertical...
I guess I was needlessly complicating the problem. The strength of the gravitational field must have been a red herring.
If the sphere is indeed floating, then the upward electric force must balance the downward gravitational force, so that their magnitudes are equal. F_g=F_e=QE
So...
Homework Statement
A plastic sphere with a positive charge of 4.8 x 10^-19 C is held stationary in a gravitational field of strength 9.8 m/s^2 by an electric field of strength 1.2 x 10^5 N/C. What is the force of gravity on the sphere?
Homework Equations
F_e=qE=kQq/r^2...