Answer:
The magnitude of the electric field is 
Explanation:
Given that,
Time t = 2.10 s
Speed = 160 m/s
Specific charge =Ratio of charge to mass = 0.100 C/kg
We need to calculate the acceleration
Using equation of motion

Put the value into the formula


We need to calculate the magnitude of the electric field
Using formula of electric field



Put the value into the formula


The direction is upward.
Hence, The magnitude of the electric field is 
Answer:
0.786 Hz, 1.572 Hz, 2.358 Hz, 3.144 Hz
Explanation:
The fundamental frequency of a standing wave on a string is given by

where
L is the length of the string
T is the tension in the string
is the mass per unit length
For the string in the problem,
L = 30.0 m

T = 20.0 N
Substituting into the equation, we find the fundamental frequency:

The next frequencies (harmonics) are given by

with n being an integer number and f being the fundamental frequency.
So we get:



Answer:
t.f. are you sure that's english? it looks like not a real thing
Explanation:
So the result is not biased or affected in some way