Concept explainers
How Does the Table Know? Thinking deeply about seemingly simple observations sometimes reveals underlying truths that we might otherwise miss. For example, think about holding a golf ball in one hand and a bowling ball in the other. To keep them motionless, you must actively adjust the tension in your arm muscles so that each arm exerts a different upward force that exactly balances the weight of each ball. New, think about what happens when you set the balls on a table. Somehow, the table exerts exactly the right amount of upward force to keep the balls motionless, even though their weights are very different. How does a table know” to make the same type of adjustment that you make consciously when you hold the balls motionless in your hands? (Hint: Think about the origin of the force pushing upward on the objects.)
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ESSENTIAL COSMIC PERS.-W/MASTER.ACCESS
- Calculate the angle a person needs to lean from the vertical when 1. walking a 14 m (radius) circular track at 22 mins per mile, and Enter to 2 significant figures Angle with respect to the vertical = = 0.85 ! No, that's not the correct answer. O 2. running at 4 min per mile. Enter to 2 significant figures Angle with respect to the vertical = 6.8 Use 1 mile = 1609.4 m Sense-making: Do your results for the leaning angle during walking agree with your observations about people walking on circular tracks? Oarrow_forwardI started hiking on a trail that was 10 kilometers long at a speed of 5 km/h. My brother walked in circles around a track at 4 km/h. At the end of 2 hours, who had the greatest change in position? Explain your answer.arrow_forwardAfter completing this Lecture Tutorial, students should be able to: distinguish between scientific hypotheses and nonscientific ideas. Part 1: Comprehension of Hypotheses A scientific hypothesis needs to (1) be supported by the majority of current data and (2) be testable. An alien on Earth is wondering why a rubber ball falls back down to the ground after it is thrown into the air. It comes up with several ideas about the ball. a. Gravity is pulling the ball to the ground. b. A mystical force that cannot be measured is pushing the ball down. c. Earth's magnetic field is pulling on the rubber ball. 1. Which statement is NOT a hypothesis because it is not testable? a b c 2. Which statement is NOT a hypothesis because it is not supported by current data? a b c 3. Which statement IS a scientific hypothesis? a b c Part 2: Application to Dinosaur Extinction Below are possible scenarios explaining the extinction of the dinosaurs. a. Dinosaurs were killed off by a virus. b. A large meteorite…arrow_forward
- 8:48 4 Document (11) 2. In the space below, draw a set of x-y axes, and label the +y direction North and the +x direction East. Label the origin of the coordinate system "home". Suppose you walk 2 blocks East from home, then turn left and walk 5 blocks North, then turn right and walk 3 blocks East. On your axes, make a vector diagram of this motion. Use vector addition to find your straight-line distance from home, measured in blocks? 1. Components of vectors. The vector in this problem is a displacement vector that starts at the origin, has a magnitude of 12 km and has a direction of 35 degrees (measured counter clockwise from the +x axis). a a. Using the gridlines below (0.5 cm spacing), draw the vector. Use a scale factor of 1 km per grid line. Use a protractor and ruler to make sure your vector has the correct magnitude and direction. b. Draw a dotted line from the tip of the vector to the x axis. Using a ruler, measure the the x component in cm, and use the scale factor to convert…arrow_forwardNewton's Law of Gravitation 2. The magnitude of the acceleration of an object under the pull of Earth's gravity is given by Newton's Universal Law of Gravitation МЕ a = G R? where G is the universal gravitational constant, ME is the mass of Earth, and R is the distance of the object from the center of Earth. Let x be the distance above Earth's surface. We can rewrite the formula for the acceleration as a function of x by noting that R = Rp + x, where Rp is the radius of Earth. Therefore, МЕ a(x) = G- (RE + x)2 d. (a) Show that dx 1 1 (1 – x)* - x. (b) Use the above fact, along with the power series of 1 to determine a power 1- x 1 series for (1+x)²* (c) What is the radius of convergence for the series in part (b)? (Hint: You do not need to calculate anything. What is the radius of convergence for the power series of 1 does not change the radius of convergence.) -? This series has the same radius of convergence since taking a derivativearrow_forwardWhy is Newton's version of Kepler's third law so useful to astronomers? It is the only way to determine the masses of many distant objects. O It tells us how rapidly a planet spins on its axis. O It explains why objects spin faster when they shrink in size. O It tells us that more-distant planets orbit the Sun more rapidly.arrow_forward
- PLEASE help me with the two questions. These are the only two I need help with and this is my last question until November. Please solve number #7 from the information in 6, and please solve question #9 from the information in number 8. THANK YOU PLEASE HELP!!arrow_forwardThe image below presents a greatly exaggerated view of a planet in orbit around the Sun: Planet m M Sun In accordance with Kepler's first law of planetary motion, the shape of the orbit is an ellipse with the Sun at one focus. a) In your own words, state Kepler's second law of planetary motion, then explain how the law arises from a conservation principle (either energy or momentum). b) Again in your own words, state Kepler's third law of planetary motion, then explain how the law is derived from Newton's laws of motion and his law of universal gravitation.arrow_forwardA woman has a mass of 55.1 kg on Earth.a. What is the woman’s mass on the moon? (2 Significant figures only, type in the first box)b. What would be the woman’s weight on the moon if the gravity is 1.67 ms21.67 ms2 . (3 significant figures only, type in the second box) Do not include the units when writing your final answers in the box.arrow_forward
- s/ttyme/OneDrive%20-%20Select%20Education%20Group/ch03%20(1).pdf A In a popular amusement park ride, people stand on a circular platform which sits inside a vertical cylinder. As the cylinder and platform spin about a vertical axis, the riders feel as if they are pushed against the inside wall of the cylinder. Once the rotation rate becomes sufficiently high, the "floor" of the ride drops, leaving those inside effectively pinned to the wall. Draw force diagrams for the following cases. Is your force diagram consistent with the requirements for circular motion? Justify your answer. (a) The platform and the cylinder are spinning slowly. The people inside are standing on the floor.arrow_forwardarrow_forwardSolve the following problems and show your complete solutions for better understanding. Explain your answer for better understanding.arrow_forward
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage LearningAstronomyPhysicsISBN:9781938168284Author:Andrew Fraknoi; David Morrison; Sidney C. WolffPublisher:OpenStax