Answer:
96%
Explanation
Let A the total area of the galaxy, is modeled as a disc:
A = πR^2 = π (25 kpc)^2
And let a be the area that astronomers are able to see:
a = πr^2 = π(5 kpc)^2
The percentage that can be seen is equal to 100 times the ratio of the areas, of the galaxy and the "visible" part:
P = 100 a/A = (5/25)^2 = 100/25 = 4%
Therefore, the percentage of the galaxy not included, i.e. not seen is:
(100-4)% = 96%
Answer:
The objective lens is an optical tool used to focus an image.
Explanation:
The objective lens is an optical tool that collects light emitted by an object under observation and focuses the rays of light in order to form a real and magnified image They are used in optical instruments like microscopes, cameras, telescopes, etc. and are also referred as objective or object glasses.
Answer: 15.66 °
Explanation: In order to solve this proble we have to consirer the Loretz force for charge partcles moving inside a magnetic field. Thsi force is given by:
F=q v×B = qvB sin α where α is teh angle between the velocity and magnetic field vectors.
From this expression and using the given values we obtain the following:
F/(q*v*B) = sin α
3.8 * 10^-13/(1.6*10^-19*8.9*10^6* 0.96)= 0.27
then α =15.66°
