Investigating Terminal Velocity

829 Words2 Pages

Investigating Terminal Velocity

Introduction

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 the factors that affect the terminal velocity of a falling object.

Key Factors

· Mass of ball bearing

· Viscosity/density of the fluid

· Surface area of ball bearing

· Texture of the balls surface

· Temperature

I am going to investigate how mass affects the terminal velocity.

Prediction

I think that as the mass of the ball bearing increases so does the weight of the ball bearing, which requires more friction to balance the ball bearing's weight thus making the terminal velocity increase.

Mathematical Prediction

I think that the mass of a ball bearing is directly proportional to the terminal velocity. This is because if the mass of ball bearing doubles so does the weight of the ball bearing, which requires twice as much friction to balance the ball bearing's weight, which then doubles the terminal velocity.

Scientific Knowledge

The scientific knowledge to prove my prediction is that as the mass of the ball bearing increases the weight of the ball bearing is increased that requires more friction to balance the ball bearings weight which increases the terminal velocity.

As the ball bearing accelerates the friction acting against the falling ball bearing increases which in turn balances out the forces applied to the ball bearing which reaches the terminal velocity.

Method

The apparatus was set up as shown (in the diagram on the next page)

Two elastic bands were placed on the tube 60 cm (600 mm) apart measured to the nearest 0.1 cm. The first band placed low enough so that the ...

... middle of paper ...

...han 10% out from any group of results would be considered inaccurate and would be repeated. The uncertainties in my results after any repeated results were sufficiently small enough to keep my results reliable.

My results are not accurate enough to get a full curve of best fit because of the drag on the larger ball bearing as mentioned above.

I have found from my graph that another result could have been taken with the mass of the ball bearing between 0.88g and 2.05g.

I propose these improvements: -

· Wider tube for the ball bearing with an average mass of 2.05g

· A longer tube for a smaller percentage of error

· More results taken to increase accuracy

I suggest that more ball bearings with different masses should have had results taken to increase this investigation. Also all the improvements shown above should be taken into account to extend the experiment.

Open Document