A ball throw vertically upward with a speed of 20 m per second negativ...
Initial Speed of the Ball:
The initial speed of the ball thrown vertically upward is 20 m/s.
Speed at the Highest Point:
At the highest point of the ball's trajectory, the speed will be zero momentarily before it starts to fall back down.
Speed when Returning to the Thrower's Hand:
When the ball returns to the thrower's hand, its speed will be the same as the initial speed, which is 20 m/s. This is because in the absence of air resistance, the ball will experience the same speed on its way up and on its way down.
Explanation:
When the ball is thrown vertically upward, it will experience a constant acceleration due to gravity pulling it downwards. As it reaches the highest point of its trajectory, its speed will momentarily be zero before gravity starts to pull it back down. The ball will then return to the thrower's hand with the same speed it was initially thrown with, as long as there is no air resistance acting on it.
In the absence of air resistance, the only force acting on the ball is gravity, which causes a constant acceleration of 9.81 m/s^2. This acceleration affects the ball's speed on its way up and on its way down, resulting in the same speed when it returns to the thrower's hand.
Therefore, when the ball returns to the thrower's hand, its speed will be 20 m/s, the same as the initial speed at which it was thrown vertically upward.
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