The most active galactic nuclei are usually found at large distances from us; relatively few nearby galaxies have active galactic nuclei. What does this imply?
A) Supermassive black holes existed only when the universe was young and no longer exist today.
B) Active galactic nuclei tend to become less active as they age.
C) Active galactic nuclei can form only at large distances from the Milky Way.
D) The jets seen in many active galactic nuclei must cause them to move far away from us.
B
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Suppose a solid uniform sphere of mass M and radius R rolls without slipping down an inclined plane starting from rest. The angular velocity of the sphere at the bottom of the incline depends on
A) the mass of the sphere.
B) the radius of the sphere.
C) both the mass and the radius of the sphere.
D) neither the mass nor the radius of the sphere.
If one uses the classical expression for kinetic energy (1/2 m v2 ) for a particle traveling at half the speed of light, the result will be deficient by how many percent?
A) 13% B) 7% C) 1% D) 24% E) 27%
Engineers are designing a curved section of a highway. If the radius of curvature of the curve is at what angle should the curve be banked so that a car traveling at 29.0 m/s will stay on the road without the aid of frictional forces?
A) 23.9° B) 16.7° C) 21.0° D) 26.1°
A time-varying horizontal force F(t) = At4 + Bt2 acts for 0.500 s on a 12.25-kg object, starting at time t = 1.00 s
In the SI system, A has the numerical value 4.50 and B has the numerical value 8.75. (a) What are the SI units of A and B? (b) What impulse does this force impart to the object?