Part A

Ball $A$ is thrown vertically upward from the top of a $30-$m$-$high

building with an initial velocity of $3\frac{m}{s}.$ At the same instant

another ball $B$ is thrown upward from the ground with an

Determine the height from the ground at which they pass.

initial velocity of $18\frac{m}{s}.$

Express your answer to three significant figures and include the appropriate units.

$h=$

Part B

Determine the time at which they pass.

Express your answer to three significant figures and include the appropriate units.

$t=$