Gravitation Interactive

Gravitation Interactive Purpose: The purpose of this activity is to investigate the variables that affect the gravitational force between a planet and its moon. Procedure/Analysis: 1. A planet and its moon are shown in the simulation window. Click and drag the moon to various positions about the planet and observe the gravitational force vector. In the diagram below, draw a force vector (arrow with arrowhead) to depict the direction and relative magnitude of the force acting upon the moon at the designated locations. Note: the size of the arrow should be representative of the strength of the force. 48.4 N 62.3 N 312.2 N 35.4 N 612 N 333 N 62.3 N 68 N 20.8 N 2. Is the relationship between gravitational force and distance of separation (between inverse!________ moon and planet) an inverse or direct relationship? ______________ Explain the evidence for your conclusion. Whenever the distance of separation is increased, the force is decreased. This shows and inverse relationship 3. Note that the simulation allows you to also display the force of the smaller moon pulling upon the larger planet. Click/tap the button to show the force acting upon the planet. Which force is largest: the force ON the smaller moon or the force ON the force on the larger planet the larger planet? _____________________________________________________ Explain the evidence for your conclusion. The mass of the larger planet is much bigger therefore the force is much larger 4. Drag the moon to various locations in order to determine the quantitative effect of distance upon the gravitational force. Examine the effect of doubling, tripling and quadrupling the distance of separation (as measured from planet's center). Consider the planet's surface to be a distance of one Earth-radius (1 R ). Use the table at the right to record data for whole-number multiples of R . Separation Distance 2•R 3•R 4•R 5•R 6•R 7•R 8•R 9•R 10 • R 11 • R 12 • R planet 134.5 76.8 planet 48.4 planet planet planet planet planet Use your data to complete the following sentences. 33.6 24.9 19.4 15.2 planet 12.3 10.2 planet 8.5 planet If the separation distance between the moon and the planet is ... 312.2 planet planet planet Force (fictional units) 4 decreased a. ... increased by a factor of 2, then the F is ______________ by a factor of _______. grav 9 decreased by a factor of _______. b. ... increased by a factor of 3, then the F is ______________ grav decreased by a factor of _______. 16 c. ... increased by a factor of 4, then the F is ______________ grav 5. Now investigate the effect of varying masses upon the gravitational force between moon and planet. Use the sliders to alter the masses and observe the effect upon the force. Use your observations to answer the following statements: If the mass of the moon is ... 2 increased by a factor of _______. a. ... increased by a factor of 2, then the F is ______________ grav 3 increased by a factor of _______. b. ... increased by a factor of 3, then the F is ______________ grav 4 decreased by a factor of _______. c. ... decreased by a factor of 4, then the F is ______________ grav d. Discuss some evidence (data values) and reasoning in which you explain the logic behind your answers to parts a-c. If the mass of the Earth is ... (see step #4) increased by a factor of _______. 2 e. ... increased by a factor of 2, then the F is ______________ grav 3 increased by a factor of _______. f. ... increased by a factor of 3, then the F is ______________ grav 4 decreased by a factor of _______. g. ... decreased by a factor of 4, then the F is ______________ grav h. Discuss some evidence (data values) and reasoning in which you explain the logic behind your answers to parts e-g. Conclusion: Develop an equation (with a proportionality constant) that describes the relationship between the gravitational force (F ), the mass of the moon (M ), the mass of the planet (M ), and the distance (d) of separation between the planet and the moon. Then support the claim (i.e., the equation) with evidence and reasoning. grav moon planet Fg= Gm1m2/d^2 The equation represents the relationship between the gravitational force because of the mass 1 and 2 which represent the mass and the moon in this scenario. The d represents the distance between the center of gravity between the objects. The increase of distance has an inverse relationship to force because whenever the distance increases, the equation is divided by a larger denominator causing a smaller force and when the mass has increased the numerator is getting larger which allows a larger number to be divided causing a larger force