A0.05 kg-coin is dropped from the top of a skyscraper that is 100 meters high. how fast is the coin traveling just before it hits the ground? a. 490 m/s b. 1960 m/s c. 44 m/s d. 31 m/s

The stopwatch used by a student to measure velocity of a pulse in a slinky was of least count 0.1 second. he stops the stopwatch when a pulse has made 3 journeys from one end to the other of the slinky. he finds the seconds hand to be at 52nd division. calculate the correct time noted by him.