A Child throws a ball vertically upwards, then catches it

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The discussion focuses on a physics problem involving a ball thrown vertically upwards with an initial velocity of 10.0 m/s and gravitational acceleration of 9.8 m/s². Participants clarify that the initial velocity is not zero because it refers to the moment the ball is released into the air, not while held in hand. The conversation emphasizes understanding the context of initial and final velocities in projectile motion. The total time of flight and maximum height can be calculated using the provided equations. This highlights the importance of distinguishing between different phases of motion when solving physics problems.
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Homework Statement


Taking the intial velocity to be 10.0 m/s, g to be 9.8m/s2 and ignoring effects of air calculate:
-the total time of flight of the ball
-the maximum height it reaches

variables:
u=10
a=9.8

Homework Equations


v=u+at
x=vt-1/2at

The Attempt at a Solution


I've recently switched to Physics at school and I'm unsure about this question. Why isn't the intial velocity zero if it is being thrown up?
 
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lasisdabomb said:

Homework Statement


Taking the intial velocity to be 10.0 m/s, g to be 9.8m/s2 and ignoring effects of air calculate:
-the total time of flight of the ball
-the maximum height it reaches

variables:
u=10
a=9.8

Homework Equations


v=u+at
x=vt-1/2at

The Attempt at a Solution


I've recently switched to Physics at school and I'm unsure about this question. Why isn't the intial velocity zero if it is being thrown up?

Because the problem says the initial velocity upward is 10m/s. Why do you think it should be zero?
 
Take your hand and pick up a ball.
Turn your hand over, so that the ball is resting in your palm.
Relax your fingers.
This is a ball with a zero vertical velocity. :wink:
 
lasisdabomb said:
Why isn't the intial velocity zero if it is being thrown up?
When problems about trajectories refer to initial and final velocities, they mean the initial and final velocities while in the air. The velocity whilst still in the hand or after hitting the ground are not apropriate because in those phases there are forces other than gravity (and air resistance) acting.
 
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