Free Fall Lesson

Free Fall

By Brendan Ross

In a separate tab, open the Free Fall Tower Gizmo. Experiment first by taking any object and dropping it from each height, in VACUUM.

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Free Fall Tower Gizmo

Multiple Choice

What happens to the FINAL speed as the object is dropped from a higher height?

• The object's final speed is slower as it's dropped from higher heights.

• The object's final speed is faster as it's dropped from higher heights.

• The object's final speed doesn't change as it's dropped from higher heights.

• There is no pattern to the object's final speed as it's dropped from higher heights.

Experiment with TWO objects dropped from the same height in a VACUUM.

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Step 2

Multiple Choice

When two objects in a vacuum are dropped from the same height.....

• Both objects will float in the air.
• The lighter object will fall faster than the other.

• Both objects will fall at the same rate and hit the ground simultaneously.
• the heavier object will fall faster and hit the ground first

Free Fall

When there is no drag from an atmosphere, the only force acting on a falling object is weight from the gravitational field. This situation is called FREE FALL. In Free fall, all object on planet earth will accelerate at the same rate. So if they are dropped from the same height, they will:
-Have the same acceleration
-Fall at the same speed
-hit the ground at the same time.

Experiment with ONE object dropped from each height in AIR.

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Step 3

Categorize

Options (3)

It begins to accelerate downwards

The acceleration slows as it's falling

it stops accelerating and moves at constant velocity

What happens to the ping pong ball as it's dropped from the 40 m mark?

First

Second

Third

Terminal Velocity

At first, the ball falls and accelerates from each height in atmosphere. But the lighter objects (especially) will begin to slow their acceleration....They are still getting faster, but they aren't speeding up as quickly.
Eventually, the objects reach a point where they no longer speed up, and they move at a constant speed. It is the fastest they can go. This is called TERMINAL VELOCITY.

The motion of the objects is determined by the forces acting on them.

When only weight pulls on them, the objects all accelerate. AND they accelerate at the same rate.


When there is an atmosphere, the gas creates DRAG on the objects as they fall.

Draw

Draw a force diagram for the objects when they are falling in a vacuum.

Draw

Draw a force diagram for the objects when they are falling in atmosphere, but still SPEEDING UP.

Draw

Draw a force diagram for the objects when they are falling in atmosphere, but are no longer accelerating (TERMINAL VELOCITY).

Multiple Select

Choose all the true statements

• In an atmosphere, all objects fall at the same rate

• In a vacuum, all objects fall at the same rate

• Terminal velocity occurs when the forces are balanced on an object

• Terminal velocity occurs when an object has only weight.

• Free fall is when only weight pulls on an object.