Photoelectrons liberated from the cathode of a photo cell by light of wavelength 136nm are stopped effectively by a reverse potential difference of 6.6 v. calculate planck's constant.

When an object moves in uniform circular motion, the direction of its acceleration is a) in the same direction as its velocity vector. b) in the opposite direction of its velocity vector c) is directed toward the center of its circular path. d) is directed away from the center of its circular path. e) depends on the speed of the object.

Choose a synonym for the underlined homonym (a word with two or more meanings). i did not expect the boat to rock so much. a. boulder c. astound b. sway d. shock

What kind of simple machine is a catapult?