Any object thrown upwards will be pulled back by the earth's gravitation field and will experience a negative acceleration (or deceleration) equal in magnitude to g (acceleration due to gravity). This will continue to decelerate the object till its velocity falls down to 0, at which point, its height will be the maximum that it will reach. Afterwards, the object starts falling down and during this motion, the object will accelerate at a value of -g and continue to accelerate till it reaches the terminal velocity or hits the ground. This upward and downward motion has some interesting observations: The velocity at any location will be same (in magnitude), but only reversed in direction (between going up and falling down). The time required to go up will the same as that required for falling down.
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