Questions: Read the case study above and answer the following questions.
Divide into pairs and explain Galileo's experiment to your friend.
Write down an aim and a hypothesis for Galileo's experiment.
Write down the result and conclusion for Galileo's experiment.
Research project : experimental design
Design an experiment similar to the one done by Galileo to prove that the acceleration due to gravity of an object is independent of the object's mass. The investigation must be such that you can perform it at home or at school. Bring your apparatus to school and perform the experiment. Write it up and hand it in for assessment.
Case study : determining the acceleration due to gravity 1
Study the set of photographs alongside showing the position of a ball being dropped from a height at constant time intervals. The distance of the ball from the starting point in each consecutive image is observed to be:
${x}_{1}=0$ cm,
${x}_{2}=4,9$ cm,
${x}_{3}=19,6$ cm,
${x}_{4}=44,1$ cm,
${x}_{5}=78,4$ cm and
${x}_{6}=122,5$ cm. Answer the following questions:
Determine the time between each picture if the frequency of the exposures were 10 Hz.
Calculate the velocity,
${v}_{2}$ , of the ball between positions 1 and 3.
Calculate the acceleration the ball between positions 2 and 5.
$$a=\frac{{v}_{5}-{v}_{2}}{{t}_{5}-{t}_{2}}$$
Compare your answer to the value for the acceleration due to gravity (
$\mathrm{9,8}\phantom{\rule{2pt}{0ex}}m\xb7$ s
${}^{-2}$ ).
The acceleration due to gravity is constant. This means we can use the equations of motion under constant acceleration that we derived in
motion in one dimension to describe the motion of an object in free fall. The equations are repeated here for ease of use.
Experiment : determining the acceleration due to gravity 2
Work in groups of at least two people.
Aim: To determine the acceleration of an object in freefall.
Apparatus: Large marble, two stopwatches, measuring tape.
Method:
Measure the height of a door, from the top of the door to the floor, exactly. Write down the measurement.
One person must hold the marble at the top of the door. Drop the marble to the floor at the same time as he/she starts the first stopwatch.
The second person watches the floor and starts his stopwatch when the marble hits the floor.
The two stopwatches are stopped together and the two times substracted. The difference in time will give the time taken for the marble to fall from the top of the door to the floor.
Design a table to show the results of your experiment. Choose appropriate headings and units.
Choose an appropriate equation of motion to calculate the acceleration of the marble. Remember that the marble starts from rest and that it's displacement was determined in the first step.
Write a conclusion for your investigation.
Answer the following questions:
Why do you think two stopwatches were used in this investigation?
Compare the value for acceleration obtained in your investigation with the value of acceleration due to gravity (
$\mathrm{9,8}\phantom{\rule{2pt}{0ex}}m\xb7s{}^{-2}$ ). Explain your answer.
Questions & Answers
how to know photocatalytic properties of tio2 nanoparticles...what to do now
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
In this morden time nanotechnology used in many field .
1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc
2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc
3- Atomobile -MEMS, Coating on car etc.
and may other field for details you can check at Google
Azam
anybody can imagine what will be happen after 100 years from now in nano tech world
Prasenjit
after 100 year this will be not nanotechnology maybe this technology name will be change .
maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
Azam
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
Prasenjit
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
Damian
silver nanoparticles could handle the job?
Damian
not now but maybe in future only AgNP maybe any other nanomaterials
Azam
Hello
Uday
I'm interested in Nanotube
Uday
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
Prasenjit
can nanotechnology change the direction of the face of the world