Answer:
The ratio (U₁/U₂) = 6
Explanation:
U, the potential energy is given as
U = kqQ/r
k = Coulomb's constant
q = charge we're concerned about
Q = charge of the negative plate of the capacitor
r = distance of q from the negative plate of the capacitor.
For charge q₁
U₁ = kq₁Q/s
U₂ = kq₂Q/2s
But q₂ = q₁/3
U₂ becomes U₂ = kq₁Q/6s
U₁ = kq₁Q/s
U₂ = kq₁Q/6s
(U₁/U₂) = 6
1) 
When both the electric field and the magnetic field are acting on the electron normal to the beam and normal to each other, the electric force and the magnetic force on the electron have opposite directions: in order to produce no deflection on the electron beam, the two forces must be equal in magnitude

where
q is the electron charge
E is the magnitude of the electric field
v is the electron speed
B is the magnitude of the magnetic field
Solving the formula for v, we find

2) 4.1 mm
When the electric field is removed, only the magnetic force acts on the electron, providing the centripetal force that keeps the electron in a circular path:

where m is the mass of the electron and r is the radius of the trajectory. Solving the formula for r, we find

3) 
The speed of the electron in the circular trajectory is equal to the ratio between the circumference of the orbit,
, and the period, T:

Solving the equation for T and using the results found in 1) and 2), we find the period of the orbit:

A = h / n => h = a*n
a = 0.290 hit / time
n = 300 times
=> h = 0.290 hit / time * 300 time = 87 hits
Answer: 87 hits
Answer:

Explanation:
The standard form of the 2nd order differential equation governing the motion of mass-spring system is given by

Where m is the mass, ζ is the damping constant, and k is the spring constant.
The spring constant k can be found by




The damping constant can be found by



Finally, the mass m can be found by



Where g is approximately 32 ft/s²

Therefore, the required differential equation is


The initial position is

The initial velocity is
