An airplane flying horizontally with a speed of 500 km/h at a height of 800 m drops a crate of supplies (see the following figure). If the parachute fails to open, how far in front of the release point does the crate hit the ground?

How do astronomers know that the luminous regions of active nuclei of active galaxies are very small?

a. Their nuclei are much brighter than expected. b. The orbits of stars near the center of the galactic nuclei are faster than expected. c. The luminosity of the nuclei varies over short times. d. The color of the nuclei is different than expected.

Imagine that we put a raisin cake into the oven, with each raisin separated from the others by 1 cm. An hour later, we take it out and the distances between raisins are 3 cm. If you lived in one of the raisins and watched the other raisins as the cake expanded, which of the following would you observe?

A) All raisins would be moving away from you at the same speed. B) More distant raisins would be moving away from you faster. C) More distant raisins would be moving away from you more slowly. D) It depends: If you lived in a raisin near the edge of the cake, you'd see other raisins moving away from you, but they'd be coming toward you if you lived in a raisin near the center of the cake. E) The raisins would be expanding too, so you'd never notice any changes in the cake.

Use the appropriate relativity formula given in the text to answer the following. Isabella is moving by you at a speed of 0.8c. Although 1 minute passes on your watch, how much time will you see pass on her watch?

A) 36 seconds B) 1 minute C) 48 seconds D) 100 seconds

A solid cylinder is rolling without slipping. What fraction of its kinetic energy is rotational?

A) 1/3 B) 2/3 C) 1/2 D) 1/4 E) 3/4