<< Chapter < Page Chapter >> Page >

Questions:  Read the case study above and answer the following questions.

  1. Divide into pairs and explain Galileo's experiment to your friend.
  2. Write down an aim and a hypothesis for Galileo's experiment.
  3. 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:

  1. Determine the time between each picture if the frequency of the exposures were 10 Hz.
  2. Calculate the velocity, v 2 , of the ball between positions 1 and 3.
    v 2 = x 3 - x 1 t 3 - t 1
  3. Calculate the velocity, v 5 , of the ball between positions 4 and 6.
    v 5 = x 6 - x 4 t 6 - t 4
  4. Calculate the acceleration the ball between positions 2 and 5.
    a = v 5 - v 2 t 5 - t 2
  5. Compare your answer to the value for the acceleration due to gravity ( 9,8 m · 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.

v i = initial velocity ( m · s - 1 ) at t = 0 s v f = final velocity ( m · s - 1 ) at time t Δ x = displacement ( m ) t = time ( s ) Δ t = time interval ( s ) g = acceleration ( m · s - 2 )
v f = v i + g t
Δ x = ( v i + v f ) 2 t
Δ x = v i t + 1 2 g t 2
v f 2 = v i 2 + 2 g Δ x

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.


  1. Measure the height of a door, from the top of the door to the floor, exactly. Write down the measurement.
  2. 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.
  3. The second person watches the floor and starts his stopwatch when the marble hits the floor.
  4. 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.
  5. Design a table to show the results of your experiment. Choose appropriate headings and units.
  6. 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.
  7. Write a conclusion for your investigation.
  8. Answer the following questions:
    1. Why do you think two stopwatches were used in this investigation?
    2. Compare the value for acceleration obtained in your investigation with the value of acceleration due to gravity ( 9,8 m · s - 2 ). Explain your answer.

Questions & Answers

a perfect square v²+2v+_
Dearan Reply
kkk nice
Abdirahman Reply
algebra 2 Inequalities:If equation 2 = 0 it is an open set?
Kim Reply
or infinite solutions?
Embra Reply
if |A| not equal to 0 and order of A is n prove that adj (adj A = |A|
Nancy Reply
rolling four fair dice and getting an even number an all four dice
ramon Reply
Kristine 2*2*2=8
Bridget Reply
Differences Between Laspeyres and Paasche Indices
Emedobi Reply
No. 7x -4y is simplified from 4x + (3y + 3x) -7y
Mary Reply
is it 3×y ?
Joan Reply
J, combine like terms 7x-4y
Bridget Reply
im not good at math so would this help me
Rachael Reply
how did I we'll learn this
Noor Reply
f(x)= 2|x+5| find f(-6)
Prince Reply
f(n)= 2n + 1
Samantha Reply
Need to simplify the expresin. 3/7 (x+y)-1/7 (x-1)=
Crystal Reply
. After 3 months on a diet, Lisa had lost 12% of her original weight. She lost 21 pounds. What was Lisa's original weight?
Chris Reply
preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
can nanotechnology change the direction of the face of the world
Prasenjit Reply
At high concentrations (>0.01 M), the relation between absorptivity coefficient and absorbance is no longer linear. This is due to the electrostatic interactions between the quantum dots in close proximity. If the concentration of the solution is high, another effect that is seen is the scattering of light from the large number of quantum dots. This assumption only works at low concentrations of the analyte. Presence of stray light.
Ali Reply
the Beer law works very well for dilute solutions but fails for very high concentrations. why?
bamidele Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
Got questions? Join the online conversation and get instant answers!
QuizOver.com Reply

Get the best Algebra and trigonometry course in your pocket!

Source:  OpenStax, Maths test. OpenStax CNX. Feb 09, 2011 Download for free at http://cnx.org/content/col11236/1.2
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Maths test' conversation and receive update notifications?