Investigation of the formation of Craters (energy)

Investigation of the formation of Craters

Introduction:

When a falling object hits the ground the kinetic energy it has is transferred to the ground, and if the force of the fall is large enough, a crater would be created. In this investigation we are going to try to find out the effect of the mass of object dropped and the height from which they dropped on the size and depth of the crater formed in a box of sand. In essence we are going to change the amount of potential energy in the object that we are dropping and see observe its effects on the craters produced.

Hypothesis:

My hypothesis if that the size and depth of the crater would increase as we increase the mass of the object dropped, and the size and depth of the crater would also increase as we increase the height from which the object is dropped.

Diagram and apparatus:

For this investigation we are going to be dropping various objects into sand, the following apparatus will be used:

Stand, clamp, box containing damp sand, a meter rule, marbles and plastacine (used a dropping objects), beakers, water measuring devises (ruler, compass, and a splint), and an electronic scale will be used. Below is how the apparatus for the investigation will be set out:

Also a beaker and about 100ml of water is needed to wet the sand before use to obtain the best results.

Trial and Improvement:

Before the results can be obtained from the investigation a trail run needs to be made to verify that the experiment is set up in the right way where the variables (such as height and mass of the object dropped) in the investigation can be altered easily and would produce accurate results.

This is a preview of the whole essay

The apparatus needed for the investigation are obtained and set up the arrangement shown on the previous page. The sand was contained in a lunch-box sized square box and is filled to 2 cm from the rim; it is wetted evenly with approximately 100ml of water. We then dropped a marble with a mass of 21.32 grams into the sand from various heights from 20 cm to 80cm to test if the marble makes an even, rounded crater. Generally the crater that the Marble made was rounded and the size of the crater seem to increase with the increase in the height from which the marble is dropped. However we noticed that with a height of more than 60cm from the box of sand the object cannot be dropped from a clamp on a stand, as the stand is not long enough so the object has to be dropped by hand. We found in the trial of the experiment that it was hard to see the measurements on the meter rule as it was far away from the object to be dropped, and it was hard to hold the ruler up at all times without it wobbling.

Based on this trial of the investigation we decided to change the layout of the experiment the meter rule is to be held on the stand with a clamp making it easier to see measurements and the results would be more accurate with the stand holding the ruler up rather then a person. And to eliminate sand on the workbenches a try will be placed under the stand and box of sand.

Method:

Below are the step by step instructions by which our group of two people had done the experiment:

Get out all the apparatus required to conduct the experiment, as shown in the apparatus section and the diagram on the previous page.

Set up the apparatus to the diagram shown on the previous page, The sand is wetted with approximately 100ml of water to make it damp. The sand is leveled so the surface is flat, a small ruler was used by us to level the sand

We clamped the 0mm mark of the ruler so that it is level with the surface of the sand.

Then we obtained a piece of polystyrene with a mass of approximately 19 grams, we rolled it into the shape of a sphere, so the crater made would be rounded and the diameter and depth of the crater would be even. The ball is rapped with a layer of aluminum foil to prevent sand sticking onto the ball, the mass is weighed again (on a electronic scale) so that the total mass is 20 grams.

We secured the ball of polystyrene onto the clamp as shown on the diagram page, and raised the clamp so the base of the ball is inline with the 20 cm mark of the meter rule.

After making sure that the sand is loose and flat we loosened the clamp and let the object fall into the sand.

After that we carefully removed the ball from he sand measured the marked off the diameter of the crater made with a compass and put it against a ruler to see what obtain the measurement for the diameter, the depth of the crater is obtained by using a wooded splint which is inserted into the crater and the depth marked off with a pencil from the surface of the sand and the distance measured.

The sand is loosened and flattened again for a repeat of the drop of the ball at the same height, the repeat is done twice so there is three sets of results, where the average would be taken.

The height of the drop is then changed and the object would be dropped from these distances 40cm, 60cm, 80cm and 100cm. Beyond the 60cm height the object was dropped by hand. For the every height 3 drops will be done and points 5 to 8 will be repeated for each drop.

After that the mass of the object was changed, by using different sizes of polystyrene pieces in all the following masses were also used: 40g 60g and 80g. Each mass is dropped from the height of 40 cm, and three repeats are done.

An marble of mass 20g is also used for dropping, steps 5 to 8 is repeated.

The results obtained are to be recorded and set onto a table later.

This investigation does not involve much dangerous apparatus and procedures, goggles and gloves do not need to be worn. However care was taken in the handling of sand, we washed our hands after the experiment so that it does not get into our eyes and clothes. Stands, clamps and other hard metal objects was handled with care to avoid injury. Mess of sand was avoided by using trays and clearing up after the experiment. Also throwing and messing about with sand must be avoided.

We made the investigation a fair one by only changing one variable in the experiment at one time, the sand was kept level and was wetted with 100ml of water every time a new box of sand was used. The 0 mm mark of the meter rule was always kept level to the surface of the sand, and the base of the object to be dropped was always kept inline with the mark on the meter rule which was the intended drop height. Also, as far as we can, we tried to use the same box to contain the sand that the object will land on.

Results:

Below are the results we obtained from the investigation: