You are a novice telescope builder. Should you attempt a 6" Newtonian or Cassegrain reflector first? Why?
What will be an ideal response?
The Newtonian uses only a curved main mirror and a small flat secondary. The primary for the Cassegrain also needs a hole to be drilled in its center, and its small secondary is convex in shape, harder to make than the flat for the Newtonian.
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Which are NOT fundamental particles?
A: Protons. B: Quarks. C: Leptons. D: Bosons. E: Electrons.
An alpha particle is a nucleus of helium. It has twice the charge and four times the mass of the proton
When they were very far away from each other, but headed toward directly each other, a proton and an alpha particle each had an initial speed of 0.0030c, where c is the speed of light. What is their distance of closest approach? Hint: There are two conserved quantities. Make use of both of them. (c = 3.00 × 108 m/s, k = 1/4??0 = 8.99 × 109 N ? m2/C2, e = 1.60 × 10-19 C, mproton = 1.67 × 10-27 kg) A) 2.1 × 10-13 m B) 3.3 × 10-13 m C) 2.6 × 10-13 m D) 2.9 × 10-13 m
The diagram below shows the position of a long straight wire perpendicular to the page and a set of directions labeled A through H. When the current in the wire is directed up out of the page, the direction of the magnetic field at point P is
a.
D.
b.
E.
c.
F.
d.
G.
e.
H.
The highest frequency visible light is
a. violet b. red c. blue d. green e. yellow