Investigation of Falling Cake Cases

2155 Words5 Pages

Investigation of Falling Cake Cases

Planning and Introduction:

To begin I will explain the term terminal velocity. Terminal velocity

is the maximum speed that a given fallen object can obtain.

Terminal velocity is obtained in this way; when an object first starts

falling, it accelerates for some while after starting. Eventually the

force upwards due to the air flowing over the objects body is equal to

the weight acting downwards, and it no longer accelerates.

We can also obtain by using Newton's 2nd law how there is no

acceleration on the falling object. We know that when there is a

greater gravitational force moving on a falling object than a

frictional force, that it is accelerating. However when both these

forces equalise, a constant speed is present. Therefore the total net

force on that object is 0. By using Newton's equation of Force = Mass

X Acceleration, and inducing the fact that F = 0, and that mass can

not equal zero, that the acceleration must also be zero.

Diagram to Explain Terminal Velocity:

I will vary two factors in this experiment to determine their affect

on terminal velocity; these will be the drop height and weight. I will

record the time taken for a cake case, or a stack of cake cases, to

fall from a certain height and record the results. To make sure that I

am only recording the time when the object has achieved terminal

velocity I will drop the object from 20cm above the height and start

timing when it comes past that point.

Diagram:

Factors that affect terminal velocity:

The accelerating force acting on all falling objects is gravity, and

if it wasn't for air resistance everything would fall at the same

rate, (as on the moon). However due to air resistance, things fall at

different speeds for a number of reasons. The drag of an object (its

shape and area), in comparison to is weight, is what alters terminal

velocity.

Therefore we can determine that three things that can affect the

Open Document