Craters form when an object strikes the surface of a planet, moon, or other space object. Craters are found here on earth as well as the moon and most other planets. The energy from the impact of an object such as a meteorite is transferred to the surface that it strikes.
The energy from the impact forces the surface it strikes to move. The crater can change depending on the size, mass, and speed of the object and the type of surface it falls onto. The angle that the object strikes the surface will also be a factor. Aim:When a falling object hits the ground some of 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 only if there is no rebound or bounce. In this investigation we are going to find out the effect that different masses of object dropped from a fixed height of 2. 05meters has on the depth of the crater formed in a box of powder (starch), and the time taken for it to reach the surface of the starch.
Prediction: I predict that the greater the mass, the larger the impact crater. Hypothesis:As the mass of an object increases, the potential energy would increases due to the equation gpe=mgh, for this reason, the kinetic energy will also increase, and this causes an increase in the size of impact crater. If the mass is increased, but the gravitational force and height above the sand stay the same, the gravitational potential energy will increase, and also the kinetic energy of the impact will increase too. The scientific knowledge that supports this is that the Ball Bearing has Gravitational Potential Energy (Mxgxh=G. P.
E. ) and as it falls the Gravitational Potential Energy converts into kinetic energy (1/2MxV2 =K.E. ). The pull of gravity on Earth is 9. 81 Newtons/kg or 9. 8 Metres/sec .
This means the higher the ball bearing the more Gravitational Potential Energy it has so the more kinetic energy it gains. When it hits the powder the kinetic energy is transferred into the powder as heat and more kinetic energy moving the powder out of the way. So therefore the more energy the ball bearing has when it hits the powder the deeper the crater it should make. Crater size is related to the mass and velocity of the impacting body. Mass and velocity can be combined to find the kinetic energy of a ping pong ball.Increasing either the mass or the velocity of the ping pong ball increases the kinetic energy of the impact. Kinetic energy means energy in motion, the formula for kinetic energy is, ke=1/2 x m x (v)i?? GPE = KE GPE=massgravityheight If we only change the height but not the mass: G mass (velocity) i?? The formula shows that kinetic energy is directly proportional to the square of the speed and to the mass of an object.Which means that the more mass an object contains, the more kinetic energy it has, meaning that the amount of weight an object contains has an effect on the type of collision Therefore, compared to the changes in height, it has less effect on a crater, because if the height increases the velocity will also increase, and in the formula shown above velocity is squared which means its double, but the mass is factored which is half of original.
Changing mass:Also, I think that the time taken (velocity) for the ball to hit the surface will all be the same no matter how the mass increases, because when the ball reaches the ground all the gravitational potential energy is converted into kinetic energy, therefore this will only be true if we live in a perfect world without any factors affecting the ball when it drops. When the ball drops from ladder, there is air resistance that might change the velocity, and also because of the water inside the ball, when it drops there might be unbalanced. To calculate the speed of the ball when it hits the ground;Ping Pong ball weight + (20 ml of water =20grams) Meter Ruler (measuring the height) Ruler (measuring the depth) Container (putting powder) Powder (Starch) Stop watch (finding the time) Strings (measuring the depth) Ladder Wood Water Syringes Method: 1 Gather all the equipments 2 Set up the ladder, wood and container with starch it in. 3 Put the container directly 90 degree down from where the wood is placed, and make a mark on it, so when it is moved we can put it at the original place.
And also make a mark of where the length of the wood sticking out to make it a fair test.Also draw a line around the level of the powder it has in order to keep the same height when the ball reaches the surface of the powder. 4 Take our five different ping pong balls, and add weights on it with syringes, by injecting water in the ball. 1. No weight (2.
7gram) 2. 5ml of water (5 gram) 3. 10ml of water (10 gram) 4. 15ml of water (15 gram) 5. 20ml of water (20 gram) 5 Get a stop watch and get ready to time it 6 Drop the ball from where the wood is place down to the container, and as soon as the ball is dropped stop the stopwatch. 7 Record the time taken 8 Carefully take the ball out of the container.And if there is some powder stuck on the bottom of the ball try to put it back 9 Place a ruler near the crater without pressing. Cut a short length of a string to measure the depth of the hole.
Cut the extra bit off. 10 Cut it, and measure the length of the string with ruler 11 Record the result. 12 Flatten the surface of the ruler by shaking the container, and then use ruler or other flat material to smooth it. 13 Repeat step 5-12 four more times. 15 Repeat step 5-12 five times with 5ml of injecting water 17 Repeat step 5- 12 five times with 10ml of injecting water.19 Repeat step 5- 12 five times with 15ml of injecting water 21 Repeat step 5- 12 five times with 20ml of injecting water Variables..
…. Independent: Mass is the only variable that I am changing. Therefore, in my experiment even though the mass is changing the size of the object will be kept the same in order to measure the depth of the crater, because if the size changes different width will be formed. The different masses of the object that I will be using are 1. No weight (2.
7gram) 2. 5ml of water (5 gram) 3. 10ml of water (10 gram) 4.
15ml of water (15 gram) 5.20ml of water (20 gram) Mass will be measured in kilograms. To change the mass I will be using syringes and injects the amount of water that I want into the ball. Dependent: The dependant variable is the variable dependant on others to produce a result and also what I am trying to find out about. The the dependent variable in my experiment will be the depth of crater that is formed each time I drop the ball, and the time taken for it to reach the surface of the powder.
The depth of the crater will be measured in millimetre, and the time taken will be measured in seconds. Controlled:The most important controlled variables are the Height and the directed surface; these two things will need to be kept constant throughout the experiment this is to ensure these variables compliment and help produce accurate results when varying masses. In order to keep the height and the directed surface the same, the wood shown on method step two is shown in order to drop it from the same place, and also in order to dropped it at the directed surface, where the container is place also need to be kept the same, this is because if the height of the dropping object increases the gravitational potential energy would also increase.Moreover, the same brand of ping pong balls needs to be used, since different brands of ping pong balls have different sizes. Also try to keep the same person dropping the ball, and same person recording the stopwatch and keep the same stopwatch. This is because, different person might drop the ball in different ways, and same as the stop watch, and this might affect the result. In addition, every time the ball is dropped, the powder needs to be resurface because if the surface is not flat or the same, the result might get affected.In order to do this, every time when a drop is done, the container needs to be shaken to flatten the surface in order to produce a smooth surface.
When the ball has been dropped it must be treated the same every time it needs to be really carefully removed from the crater every time, without affecting the depth. The angle at which I drop the object will also affect the size of the crater. To make it a fair test I will have to drop the object from the same angle ever time. Which I will drop the ball from 90 degrees above the surface of the powder. Results.
.. Mass of balls measured in gram (x10-3kg) Number of ballsMass of balls grams(x10-3kg) Uncertainties 1 Descriptions of Each ball in detailed: Ball 1 (x10-2m)Number of Trial Depth of crater (x10-2m) Uncertainties in Depth using ruler (x10-2m) Mass of the ball (x10-3kg) Uncertainties in Measuring the mass of the ball (x10-3kg) 1The first reading shows that this reading is quite reliable since that the results in each trial are very close to each other. UNCERTAINTIES of BALL 1 -Depth of crater measured in ruler (0-2m): Trials Depth of the crater From the table above, the differences compared to calculated average isn’t that much difference, and I think that the in ball 1, the measurement of the depth of the crater are quite close to each other. Ball 2 (x10-2m): Trials Depth of crater (x10-2m) Uncertainties in Depth using ruler (x10-2m) Mass of the ball (x10-3kg) Uncertainties in Measuring the mass of the ball (x10-3kg)In this reading, there is one number that is quite different from the others, even though the results in the second reading seem to be close enough.
2. 50cm deep of crater shows that it might be an outlier in this row of data, because 2. 3 and 2. 1 appeared more than twice, but 2. 5 only appeared once.
UNCERTAINTIES of BALL 2 -Depth of crater measured in ruler.This result seem to be a little different from the previous readings, the minimum number is 2. 3cm and the maximum is 2. 7cm, and the gap between them is 0. 4cm which is quite a lot, and it could have affected the number in the average, by lowering down. UNCERTAINTIES of BALL 3-Depth of crater measured in ruler As you can see that, this is the increases of the depth of crater each time the masses of the balls are increased. From the table above, you can see that the in the first time it increases the most, because it starts from no water and then increase 5grams, but then as u can see, the normal average increase weight will be around 0.
36cm, but from the third ball which is 1. 56cm to fourth ball 2.64 it did not increase as much as I thought it would be, and the number is a lot lower than the average amount.