3
select the correct answer.
what happens to a light ray passing through the center of a lens?
a. it passes without any deviation.
b. it converges to the focal point.
c. it travels parallel to the principal axis.
d. it diverges away from the principal axis.

Answer quickly (15 points) a comet is approaching earth. describe earth’s gravitational pull as the comet gets closer to it. a. remain constant b. increase c. decrease d. reversed

Consider a double atwood machine constructed as follows: a mass 4m is suspended from a string that passes over a massless pulley on frictionless bearings. the other end of this string supports a second similar pulley, over which passes a second string supporting a mass of 3m at one end and m at the other. using two suitable generalized coordinates, set up the lagrangian and use the lagrange equations to find the acceleration of the mass 4m when the system is released. explain why the top pulley rotates even though it carries equal weights on each side.

Which missing item would complete this alpha decay reaction ? > 228/88ra + 4/2he a.224/96 rn b. 232/90 th c. 230/92 u d. 235/92 u