Terminal velocity of a falling ball.

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In the investigation I will enquire the factors that affect the terminal velocity of a falling ball bearing in a fluid. When an object falls through a fluid it accelerates until it reaches its terminal velocity. At this speed the forces acting on it are balanced. My task is to investigate this very situation.

* Stop watch

* Large wide tube

* Micrometer

* Ball bearings

* Vegetable oil (fluid)

* Retort stand

* Meter ruler

* Thermometer

* Boss

* Clamp

Terminal velocity of an object occurs when the opposing force is equal to the accelerating force; the net force on the object is zero. The object stops accelerating and carries on at a steady speed. (Diagram below to explain).

Figure 1 Figure 2 Figure 3

In figure 1,the ball at the top is stationary the fluid resistance in terms of viscosity is zero. In figure 2 fluid resistance increases thus slowing down the rate of acceleration. In figure3 the fluid resistance balances the weight of the ball bearing hence the ball is no longer accelerating. The speed of the ball at this time is in its terminal velocity.

This explanation above informs us of what is expected to happen through out the investigation. It shows the ball bearing will reach terminal velocity before it reaches the bottom of the tube due to the viscosity applied by the fluid.

The factors that are believed to affect this investigation are the mass of the ball bearing since it will determine the speed of how fast it will fall through the liquid. The second factor is the density of the fluid, the thicker the liquid the slower the ball bearing will fall and vice a versa, to lower the density I could heat the fluid. The final factor would have to be the surface area of the ball bearing, if streamline it will cut through the fluid and fall faster and vice a versa.
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In this investigation there are many variables that will affect the terminal velocity of ball bearings as it passes through the fluid.

Density of fluid (viscosity)-if an object if falling through a viscous fluid a force of friction is acted upon the object. In order to keep the viscosity of the fluid constant for a fair test the same fluid will be used throughout the whole investigation.

Gravitational field- the ball bearings fall through the oil due to the attraction created by the gravitational field from the Earth (gravity). In this investigation, this can be considered ...

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