A carpenter accidentally dropped his hammer from the roof top of the house he is repairing. If the hammer hits the ground after 1.68 seconds, how high is the house?

A football running back rushes 13 m straight down the playing field in 2.1 s (in the positive direction). He is then hit and pushed 3.5 m straight backwards in 1.95 s. He breaks the tackle and rushes straight forward another 21 m in 4.2 s. Part (a)  Calculate the running back's average velocity in the horizontal direction during the first interval, in meters per second.  Part (b)  Calculate the running back's average velocity in the horizontal direction during the second interval, in meters per second.  Part (c)  Calculate the running back's average velocity in the horizontal direction during the third interval, in meters per second.   Part (d)  Calculate the running back's average velocity in the horizontal direction for the entire motion, in meters per second.

Jimmy "Butterfingers" James is a stuntman that jumps off of buildings for a living. He was jumping off a building for an upcoming movie when he dropped the closed umbrella he was holding. If he was travelling at 15.6 m/s when he let go of the umbrella, (1) from what height (distance) did the umbrella fall if it took 1.25 seconds to hit the ground and (2) what was the velocity of the umbrella just before it hit the ground? Note: Show your work and proper units, and write your answers to 3 sig figs. Also, keep all numbers positive

A student throws a set of keys vertically upward to his fraternity brother, who is in a window 4.00 m above. The brother's outstretched hand catches the keys 1.70 s later. (a) With what initial velocity were the keys thrown? (b) What was the velocity of the keys just before they were caught? (Take upward as the positive direction.)