Two identical spring-loaded dart guns are simultaneously fired straight forward. one fires a regular dart; the other a weighted dart. which dart goes farther?

=force × distance a. work b. velocity c. pressure d. momentum

The space between two 15-in.-long concentric cylinders is filled with glycerin (viscosity = 8.5 × 10-3 lb·s/ft2). the inner cylinder has a radius of 1 in. and the gap width between cylinders is 0.1 in. determine (a) the torque and (b) the power required to rotate the inner cylinder at 180 rev/min. the outer cylinder is fixed. assume the velocity distribution in the gap to be linear.

Which planet do you think would be easiest for humans to colonize some day?