-1- was created in the 1600 by william gilbert
-2-When the charge is positive, electrons in the metal of the electroscope are attracted to the charge and move upward out of the leaves. This results in the leaves to have a temporary positive charge and because like charges repel, the leaves separate. When the charge is removed, the electrons return to their original positions and the leaves relax
3-
An electroscope is made up of a metal detector knob on top which is connected to a pair of metal leaves hanging from the bottom of the connecting rod. When no charge is present the metals leaves hang loosely downward. But, when an object with a charge is brought near an electroscope, one of the two things can happen.
Answer:
Explanation:
From the question we are told that
The electric filed is 
Generally according to Gauss law
=> 
Given that the electric field is pointing downward , the equation become
Here 
is the excess charge on the surface of the earth
is the surface area of the of the earth which is mathematically represented as
Where r is the radius of the earth which has a value 
substituting values
So
Here 
s the permitivity of free space with value
substituting values
Answer: 29.17m/s^2
Explanation:
Given the following :
Velocity = 525 m/s
Time = 18 seconds
Acceleration = change in Velocity with time
Using the motion equation:
v = u + at
Where v = final Velocity
u = Initial Velocity and t = time
Plugging our values
525 = 0 + a × 18
525 = 18(a)
a = 525 / 18
a = 29.166666
a = 29.17 m/s^2
I can't see numbers here, so here are all the answers:
1) the frequency is c/λ = 3e8/556e-9 = 5.39e14Hz
2) light travels at <span>299,792,458 m/s. So in nanoseconds it's 0.299792458m. This is about 1/3 of a meter which is about one foot.
3) length is L = ct = (</span>299,792,458 m/s)(6e-15) = 1.799e-6m or 1.799μm
