Concept explainers
Two thin rods are fastened to the inside of a circular ring as shown in Figure P2.42. One rod of length D is vertical, and the other of length L makes an angle θ with the horizontal. The two rods and the ring lie in a vertical plane. Two small beads are free to slide without friction along the rods. (a) If the two beads are released from rest simultaneously from the positions shown, use your intuition and guess which bead reaches the bottom first. (b) Find an expression for the time interval required for the red head to fall from point Ⓐ to point Ⓒ in terms of g and D. (c) Find an expression for the time interval required for the blue bead to slide from point Ⓑ to point Ⓒ in terms of g, L, and θ. (d) Show that the two time intervals found in parts (b) and (c) are equal. Hint: What is the angle between the chords of the circle Ⓐ Ⓑ and Ⓑ Ⓒ? (e) Do these results surprise you? Was your intuitive guess in part (a) correct? This problem was inspired by an article by Thomas B. Greenslade, Jr., “Galileo’s Paradox,” Phys. Teach. 46, 294 (May 2008).
Figure P2.42
Trending nowThis is a popular solution!
Chapter 2 Solutions
Physics for Scientists and Engineers
Additional Science Textbook Solutions
Chemistry: An Introduction to General, Organic, and Biological Chemistry (13th Edition)
Biology: Concepts and Investigations
Human Biology: Concepts and Current Issues (8th Edition)
Fundamentals Of Thermodynamics
- A ball is held at rest at position A in the figure (Figure 1) by two light strings. The horizontal string is cut and the ball starts swinging as a pendulum. Point B is the farthest to the right the ball goes as it swings back and forth. What is the ratio of the tension in the supporting string in position B to its value at A before the horizontal string was cut?arrow_forwardTwo bugs, Buzz and Crunchy, are siting on a spinning disk on a horizontal plane. Buzz is sitting halfway and Crunchy is sitting at the outer edge as shown. The radius of the disk is 0.80 m and the disk is rotating with an angular speed of 38 rpm. The coefficient of friction between the bugs and the disk are us = 0.80 and uk= 0.60. What is the magnitude of Buzz's acceleration, in m/s2? Your answer needs to have 2 significant figures, including the negative sign in your answer if needed. Do not include the positive sign if the answer is positive. No unit is needed in your answer, it is already given in the question statement. Buzz Crunchyarrow_forwardthere is a plant with density, R and m. An armored bulldozer is dispatched to the planet to drill out two spherical holes in it. The holes are R-diameter spheres with one edge touching the center of the larger sphere. What gravitational force does the hollowed-out sphere exert on a satellite (particle) of mass m positioned s from the planet's center? Hint: you can use gravitational force or gravitational potential.arrow_forward
- I am currently really struggling in my physics class and really need help. I've reached out to both my teacher and school and neither are helping me. My teacher is really hard for me to understand so when learning the material I am left confused. I really do not know how to solve this problem or any problem like this at all. I need as much help as I can get.arrow_forwardA 5.0 g coin is placed 15 cm from the center of a turntable. The coin has static and kinetic coefficients of friction with the turntable surface of μs = 0.70 and μk = 0.50. The turntable very slowly speeds up. What is the frequency of the rotation of the turntable expressed in revolutions per minute when the coin slides off? Express your answer in revolutions per minute.arrow_forwardAfter landing on an exoplanet, an astronaut constructs a simple pendulum of length 49 cm. The pendulum completes 89 full swing cycles in a time of 101 s. What is the magnitude of the gravitational acceleration in m/s2 on the exoplanet? Give your answer to 2 decimal places.arrow_forward
- A skate park is formed by two semicircles of radius R1 = 8.3 m and R2 = 1.0 m and a flat central part, as shown in the following figure. The flat part has a length L = 3.6 m. The semicircles are tangent to the horizontal in B and C and to the vertical in A and D. There is no friction in the curved parts and in the flat part the coefficient of kinetic friction is μC = 0.2. A block with mass m = 3.2 kg is dropped from A. Suppose the acceleration due to gravity is 9.8 m / s2. What is the magnitude of the velocity of the block as it passes through point B the second time? Choose one: a. 45,4 m/sb. None of the other alternatives.c. 22,7 m/sd. 11,6 m/se. 12,0 m/sf. 5,7 m/sg. 7,6 m/sh. 129,0 m/sarrow_forwardThe center of a moon of mass m = 8 × 1023 kg is a distance D = 97 × 105 km from the center of a planet of mass M = 10.9 × 1025 kg. At some distance x from the center of the planet, along a line connecting the centers of planet and moon, the net force on an object will be zero. a. Derive an expression for x. b. Calculate x in kilometers, given the variables in the beginning of the problem.arrow_forwardIf you weighed 112 N on the Moon where g = 1.6 N/kg, how much would weigh on Earth? %3D O 1.1 x 102 N O 1.7 x 104 N O 6.9 x 102 N O1.1x 104 N O 6.9 x10° Narrow_forward
- please answer this question within 30 minutes. i will upvote. Spherical particles of radius 4.50 x10-6 m are suspended in water and placed in a centrifuge. This centrifuge has a radius of 13.0 cm and spins at 255 Hz. If the terminal velocity of the particles is 2.00 m/s, what is their density? Answer in kg/m3 but do not include units in your answer.arrow_forwardA block with a mass of 1.20 kg is tied to a string and is swung in a horizontal circle, while the block remains in contact with the ground. Assume there is no friction and that the string is always parallel to the ground. The radius of the circular motion is 2.50 m and the period of the motion is 0.500 s. What is the magnitude of the tension in the string? Express your answer in N.arrow_forward39. a. With what initial speed must you throw a ball vertically for it to reach a height of 20 ft? The ball weighs 1 lb. How does your answer change if the ball weighs 2 lb? b. Suppose you want to throw a steel bar vertically to a height of 20 ft. The bar weighs 2 lb. How much initial speed must the bar have to reach this height? Discuss how the length of the bar affects your answer.arrow_forward
- Principles of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and Engineers with Modern ...PhysicsISBN:9781337553292Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning