I will be carrying out an experiment where I will be testing how a difference in mass can affect the rate at which a helicopter can fall.

If the mass of an object is changed, then I think that objects with a greater mass will fall down to earth faster and objects with less mass will fall down to earth slower. This is due to the effect of gravity. The greater the mass, the more powerful the pull of gravity.

When the air density is changed, and the particles in the air become denser, more of them will come into contact with the helicopter during its descent. This will slow down the rate of descent. If the air is less dense, fewer particles will come into contact with the helicopter and it will fall faster. The air particles pushing up against the helicopter is called Air Resistance.

The aerodynamics of a helicopter can make its fall through the air faster or slower. An aerodynamic helicopter would have a faster rate of descent, e.g. if the object falling was spherically shaped, it would fall faster as it is more aerodynamic. Another example of an object being made more aerodynamic is to add ailerons to a plane, which help them to glide better on the wind.

The initial velocity of the helicopter will alter the time that it takes to fall to the ground. This is because as the object falls through the air, it will speed up until it reaches terminal velocity. This is when an object's weight is equal to the Air Resistance, (AR). Once an object has reached this speed, it will continue to fall at a constant rate until it hits the ground. This is Newton's first law of motion. If an object starts its descent at a higher speed, it will reach terminal velocity faster and therefore it will descend faster.

When the drag and the Drag (R)

weight become equal, we

say the object has reached

Terminal Velocity.

R = W (Terminal Velocity)

Weight (W)

The Height that the object falls from will alter the time it takes to descend. The greater height the object starts from, the longer it will take to fall back down to earth. If the object only falls a short distance, it also might not have had time to reach its terminal velocity.

For this experiment, I have chosen to alter the mass that the helicopter falls with. I have chosen this variable because it is unlikely to produce any anomalous results. The results would also be straightforward to collect.

Safety during Investigation:

This investigation does not involve the use of anything dangerous. Care will be taken when taking results.

How many Observations required?

To insure accuracy, each mass alteration will be recorded 4 times, and then an average of the speeds will be taken. To further ensure accuracy, the results will be taken simultaneously on two different stopwatches.

Apparatus:

* Scissors

* A4 Paper

* Camera

* 2x 1 meter rulers

* Computer (Laptop)

* 5x Paper clips

Diagram:

Initial Testing:

The helicopter constructed from card did not work as effectively as the one constructed from paper due to its flexibility. The cardboard one was unable to turn in the air as well as the paper one. This experiment will use the paper model.

Method:

* Set up ruler and mark out a height of 2.6 meters

* Construct paper helicopter:

* Hold up helicopter at the top of the marked run

* Release the helicopter while taking pictures with a digital camera

* Time how long it takes for the helicopter to reach the ground.

* Repeat the experiment for a different mass, by adding a paperclip to the base of the helicopter.

When all the results have been collected, the final velocity can be worked out by using the formula V = U + AT. This will allow me to measure the difference in the final speeds of the helicopter, and therefore the relationship between the mass and the final velocity. I will not be using this method; I will compare the average speed of the helicopter, which I will calculate by using the formula S = D/T. This means that the speed is equal to the distance that the helicopter traveled divided by the time it took.

Design:

Analysis:

The results show that as the mass of the helicopter increased, the height at which terminal velocity was reached became lower and the length of time that the object fell at terminal velocity became less. From this we can determine that Terminal Velocity is proportional to mass. By looking at the graph that shows Mass vs. Time of descent, we can clearly see that as the mass went up, the time the helicopter took to reach the ground was decreased.

By observing the results, we can work out many other things about the helicopter, such as its acceleration:

Change in velocity (m/s) divided by Time taken in seconds.

For the 0.9 gram helicopter:

Change in velocity is speed - starting speed:

0.78490566 - 0

The change in velocity is 0.78490566

The time taken is 3.3125

The acceleration is 0.2369 meters per second.

The formula for terminal velocity is square root of ( 2W/Cd r A). W is weight, Cd is drag coefficient and r is air resistance and a is frontal area.

We were not given values for all these variables so we got measurements for terminal velocity by using the pictures we took and observing when the helicopter hit terminal velocity, then we calculated the sped but the calculation, Height that terminal velocity is reached, divided by the time it took for the helicopter to hit the ground from that point.

Evaluation:

Our experiment is not entirely accurate, due to the fact that we were unable to accurately measure when the helicopter reached terminal velocity. The results we took were fairly accurate, as there are no anomalies present.