Answer:

Explanation:
We know that the magnetic Field of the Earth is 50\mu T, so the equation for
Hall effect voltage und magnetic field are defined as,


So,



Answer:
D. Wind and solar energy help save money and reduce air pollution.
Explanation:
Answer:
12.5J
Explanation:
Given parameters:
Mass of bucket = 1.7kg
Height = 75cm = 0.75m
Unknown;
Work done on the bucket by the person = ?
Solution:
To solve this problem, we use the work done equation;
Work done = force x distance = mgh
m is the mass
g is the acceleration due to gravity
h is the height
Now, insert parameters and solve ;
Work done = 1.7 x 9.8 x 0.75 = 12.5J
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:


