physicsHELP
posted by jel .
a giant robot tosses a ball up, from a height of 80 meters, with an initial velocity of Vo = 60 m/s, use 10 m/s^2 as the acceleration due to gravity.
what will be the minimum velocity of the ball and when and where will that occur? [i don't know how you would find that.]
what will be the maximum speed, and when and where will that occur/
how many times can the ball attain a speed greater than 60 m/s but less that its maximum speed?

The velocity is the initial velocity + any velocity based on the acceleration of gravity. Gravity is a negative acceleration to an object thrown upwards. The minimum velocity will be where the ball stops going up and falls back down.
Where maximum speed occurs will depend on whether the robot catches the ball or it falls to his feet. 
Use a(t)=32 ft/s squared as the acceleration due to gravity. A ball is thrown vertically upward from the ground with an initial velocity of 56 feet per second. For how many seconds will the ball be going upward?

A vehicle changes its velocity from 90 km/h to a dead stop in 10s. Show that its acceleration in doing so is 2.5m/s2