99 1.a rock is thrown upward with an initial speed of 15 m/s on earth

a. Make a list of given quantities and quantities to find, labeled with units and appropriate algebraic signs (+,-) _x000d_
_x000d_
b. what is the acceleration of the rock?_x000d_
_x000d_
c. Calculate the rock’s height after 1 sec_x000d_
_x000d_
d. Calculate the time required to reach an upward speed of 3 m/s _x000d_
_x000d_
e. Calculate the time required to reach a downward speed of 5 m/s