Answer:
The velocity is 31.25 m/s and direction is toward west.
Explanation:
Given that,
Distance 
Magnetic field 
Mass of proton 
Radius of earth 
Radius of orbit 


We need to calculate the speed
Using formula of magnetic field


Put the value into the formula


Hence, The velocity is 31.25 m/s and direction is toward west.
Answer:
<em>The new period of oscillation is D) 3.0 T</em>
Explanation:
<u>Simple Pendulum</u>
A simple pendulum is a mechanical arrangement that describes periodic motion. The simple pendulum is made of a small bob of mass 'm' suspended by a thin inextensible string.
The period of a simple pendulum is given by

Where L is its length and g is the local acceleration of gravity.
If the length of the pendulum was increased to 9 times (L'=9L), the new period of oscillation will be:


Taking out the square root of 9 (3):

Substituting the original T:

The new period of oscillation is D) 3.0 T
Answer:
1000 Hz
Explanation:
<em>The frequency would be 1000 Hz.</em>
The frequency, wavelength, and speed of a wave are related by the equation:
<em>v = fλ ..................(1)</em>
where v = speed of the wave, f = frequency of the wave, and λ = wavelength of the wave.
Making f the subject of the formula:
<em>f = v/λ.........................(2)</em>
Also, speed (v) = distance/time.
From the question, distance = 900 m, time = 3.0 s
Hence, v = 900/3.0 = 300 m/s
Substitute v = 300 and λ = 0.3 into equation (2):
f = 300/0.3 = 1000 Hz