When a ball is thrown straight up into the air when the does the acceleration change directions?

Answer 1

Any object near the surface of the earth and not constrained experiences a

downward vertical acceleration of 9.8 meters (32.2 feet) per second2 because

of the mutual force of gravitational attraction between it and the earth.

Answer 2

Never. The acceleration is constant, from the time the ball leaves your hand

until it hits the ground. Its value is 9.8 meters /sec2 downward. . . the acceleration

of gravity.

It's the velocity of the ball that changes directions, right at the top of the arc,

where the ball stops going up and starts going down.

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What is said above is entirely correct. Here's a good way to remember this:

When you throw a ball up in the air, you have given the ball an initial velocity in the positive (up) direction. From the second the ball leaves your hand, the acceleration due to gravity constantly pulls the ball downward, slowing the upward velocity by 9.8 m/s every second. Thus, as the ball is travelling upward, the distance traveled per second continually gets shorter since the ball is slowing down. Once acceleration has slowed the ball down enough, it will stop travelling upward and start to fall back to earth. It is at this point that velocity has changed direction, as a result of the downward acceleration overpowering the upward motion of the ball.

Answer 3

Vertical force does. It's as simple as that.

Answer 4

The vertical acceleration is caused by gravity.

Answer 5

zero -9.8 m/s2