Answer:
1.25 m/s
Explanation:
m1v1+m2v2=m1v1f+m2v2f
(1425*13)+(1175*0)=(1425*v1f)+(1175*14.25)
18525+0=1425(v1f)+16743.75
1781.25=1425(v1f)
v1f=1.25 m/s
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%
Explanation:
A charge alters the space around it. This alteration of space is called the electric field. It is also defined as the electric force acting on a charged particle per unit test charge. It is given by :

Where
F is the electric force, 
The direction of electric field is in the direction of electric force. For a positive charge, the direction of electric field lines are outwards and for a negative charge, the direction of field lines are inwards.
Hence, the correct option is (c) "electric field".
Answer:b) atoms
Explanation:which are in turn made up of protons, neutrons and electrons