Two spaceships are approaching one another, each at a speed of 0.28c relative to a stationary observer on Earth. What speed does an observer on one spaceship record for the other approaching spaceship?
What will be an ideal response?
0.52c
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The picture below shows a sphere as it looks at rest. Suppose the sphere is moving to the right at about 90 percent of the speed of light. Which figure below correctly shows the shape of the sphere as you would measure it?
A) Figure A B) Figure B C) Figure C D) Figure D E) Figure E
Gino says that the analog of Gauss's law for the flow of an incompressible fluid of density ? at constant velocity 
is 
for an imaginary surface within the fluid. Lorenzo says that it is true only if the area where the fluid enters the surface and the area where it leaves the surface are both perpendicular to the velocity of the
fluid. Which one, if either, is correct? A.
B.
is not equal to zero if the fluid enters or exits at angles other than 90°.C.
D.
E.
Two men, Joel and Jerry, push against a car that has stalled, trying unsuccessfully to get it moving. Jerry stops after 10 min, while Joel is able to push for 5.0 min longer. Compare the work they do on the car
A) Joel does 75% more work than Jerry. B) Joel does 50% more work than Jerry. C) Jerry does 50% more work than Joel. D) Joel does 25% more work than Jerry. E) Neither of them does any work.
A 4.0-g bead carries a charge of 20 ?C. The bead is accelerated from rest through a potential difference V, and afterward the bead is moving at 2.0 m/s. What is the magnitude of the potential difference V?
A) 800 kV B) 400 kV C) 800 V D) 400 V E) 200 V