Download Determining the Gravitational Constant 'G' through Virtual Simulation in Physics and more Study Guides, Projects, Research Physics in PDF only on Docsity! Virtual Learning Physics Determining “G” May 11, 2020 Physics Determining “G”: May 11,2020 Objective/Learning Target: Students will use a computer simulation and graphing techniques to determine the gravitational constant “G” Quick Review #2 Suppose that an apple at the top of a tree is pulled by Earth’s gravity with a force of 1 N. If the tree were twice as tall, would the force of gravity on the apple be only ¼ as strong? Quick Review #2 No, because the twice-as-tall apple tree is not twice as far from Earth’s center. The taller tree would have to have a height equal to the radius of Earth (6370 km) before the weight of the apple would reduce to 1/4 N. Before its weight decreases by 1%, an apple or any object must be raised 32 km—nearly four times the height of Mt. Everest, the tallest mountain in the world. So as a practical matter we disregard the effects of everyday changes in elevation. Newton’s Law of Gravitation and “G” Introduction You will use a computer simulation today to reinforce your ideas of Newton’s Universal Law of Gravitation and to determine “G”. Since this is “inquiry based”, you’re not supposed to know everything going in, but learn as we walk through the lesson. You must read the following slides carefully. Let’s get started! Newton’s Law of Gravitation and “G” Website:Gravitational Force Simulation Make sure to use the HTML5 version. Select Download to get started.. Newton’s Law of Gravitation and “G” 1. Vary the masses and distance between the masses, record all your data along with the gravitational force that is given in the Sim. Record all sig figs. 2. Do this for ten different scenarios recording each in the data table. Make sure to use the entire range possible for all the parameters. The ruler is movable so you can get the distances more exactly. This will be your least accurate measurement. Make it as carefully as you can. M1 (kg) M2 (kg) r (m) F (N) X = M1M2 r² Newton’s Law of Gravitation and “G” 3. Calculate “X” using the the following portion of the gas law and record in the table. X = M1M2 r² M1 (kg) M2 (kg) r (m) F (N) X = M1M2 r² Simulation example answers
Force (N)
1.00E-05
9.00E-06
8.00E-06
7.00E-06
6.00E-06
5.00E-06
4.00E-06
3.00E-06
2.00E-06
1.00E-06
0.00E+00
oO
Force vs X
y = 7E-11x
20000
40000
60000 80000 100000 120000 140000 160000
x (kg*2/m%2)
Simulation example answers 4. Slope = Rise = (y2 -y1) Run (x2-x1) = (1.66853 x 10⁻⁷ - 7.508 x 10⁻⁹)N (2500-112.5)kg²/m² =6.67409424 x 10⁻¹¹Nm²/kg² 5. %err = (experimental value - accepted value) x 100% accepted value =6.674 x 10⁻¹¹ - 6.673 x 10⁻¹¹ x 100% = 0.1 % 6.673 x 10⁻¹¹ Additional Practice Return to the simulation and practice using Newton’s Law of Gravitation by picking mass values and a distance and calculating the Force between them using the formula and checking your answer with the simulation. F = G mM r²
