Concept explainers
Apparent weightlessness in a satellite. You have probably seen films of astronauts floating freely in orbiting satellites. People often think the astronauts are weightless because they are free of the gravity of the earth. Let us see if that explanation is correct. (a) Typically, such satellites orbit around 400 km above the surface of the earth. If an astronaut weighs 750 N on the ground, what will he weigh if he is 400 km above the surface? (b) Draw the orbit of the satellite in part (a) to scale on a sketch of the earth. (c) In light of your answers to parts (a) and (b), are the astronauts weightless because gravity is so weak? Why are they apparently weightless?
Want to see the full answer?
Check out a sample textbook solutionChapter 6 Solutions
College Physics (10th Edition)
Additional Science Textbook Solutions
College Physics
Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (4th Edition)
Tutorials in Introductory Physics
College Physics: A Strategic Approach (4th Edition)
An Introduction to Thermal Physics
Life in the Universe (4th Edition)
- Let gM represent the difference in the gravitational fields produced by the Moon at the points on the Earths surface nearest to and farthest from the Moon. Find the fraction gM/g, where g is the Earths gravitational field. (This difference is responsible for the occurrence of the lunar tides on the Earth.)arrow_forwardFor many years, astronomer Percival Lowell searched for a Planet X that might explain some of the perturbations observed in the orbit of Uranus. These perturbations were later explained when the masses of the outer planets and planetoids, particularly Neptune, became better measured (Voyager 2). At the time, however, Lowell had proposed the existence of a Planet X that orbited the Sun with a mean distance of 43 AU. With what period would this Planet X orbit the Sun?arrow_forward(a) Find the magnitude of the gravitational force between a planet with mass 7.50 1024 kg and its moon, with mass 2.70 1022 kg, if the average distance between their centers is 2.80 108 m. (b) What is the acceleration of the moon towards the planet? (c) What is the acceleration of the planet towards the moon?arrow_forward
- What is the orbital radius of an Earth satellite having a period of 1.00 h? (b) What is unreasonable about this result?arrow_forwardHello, i need help with question 5.arrow_forwardPlanet X has a radius of 6.00×10^7 m and an unknown mass. When a woman of mass 65.0 kg weighs herself on a platform which is a distance of 1.50×10^7 m above the surface of this planet, the scale reads 1200 N. a) What is the mass of Planet X? b) What is the gravitational field (g value) on the surface of planet x?arrow_forward
- Exoplanet Taphao Keow is a Jupiter-sized planet orbiting another star. It has a mass of approximately 1×10+27[kg]. Its actual radius is not currently known, but we do know that the radius of Jupiter is 7×107[m]. Question: If Taphao Keow had a radius that was the same radius as Jupiter, what would it's local surface gravitational acceleration be? O 266 [m/s2] 124 [m/s²] 70 [m/s²] O 24 [m/s²] O 14 [m/s²] It would have a gravitational acceleration far larger than any of the other answers (many orders of magnitude larger) It would have a gravitational acceleration far smaller than any of the other answers (many orders of magnitude larger)arrow_forwardScientists want to place a 4 × 103 kg satellite in orbit around Mars. They plan to have the satellite orbit a distance equal to 2.4 times the radius of Mars above the surface of the planet. Here is some information that will help solve this problem: mmars = 6.4191 x 1023 kgrmars = 3.397 x 106 mG = 6.67428 x 10-11 N-m2/kg2 1.)What is the force of attraction between Mars and the satellite? 2.)What speed should the satellite have to be in a perfectly circular orbit? 3.)How much time does it take the satellite to complete one revolution?arrow_forwardEvery few months, memes circulate claiming that certain alignments of the planets with the Earth will result in a change in the gravitational force you feel. Usually these memes state that the alignment will counteract Earth's gravity slightly so you will feel less of a gravitational pull towards the Earth. Can this ever happen? Let's look at the numbers. What is the gravitational force (in N) of the Earth on you (MĚ = 5.97 × 1024 kg, R₁ = 6380 km)? Say your mass is 64 kg. (Enter the magnitude.) What is the gravitational force (in N) of Jupiter on you when it is closest to Earth (M₁ = 1.90 × 1027 kg, R₁ = 5.88 × 108 km)? (Enter the magnitude.) By what factor would the mass of Jupiter need to increase to be equal to the gravitational force you feel from the Earth? Part 1 of 5 The gravitational force between two masses is given by -GMm r² where G = 6.67 x 10-11 m³/s²/kg. FgE Part 2 of 5 We can use this expression to determine the magnitude of the gravitational force you feel while on the…arrow_forward
- Some people believe that the Moon controls their activities. The Moon moves from being directly on the opposite side of Earth from you to be being directly overhead. Assume that the Earth-Moon (center-to- center) distance is 3.82 x 108 m and Earth's radius is 6.37 x 106 m. (a) By what percent does the Moon's gravitational pull on you increase? % (b) By what percent does your weight (as measured on a scale) decrease? %arrow_forwardI don't get why this statement is not accurate. "The gravitational force of the planet on a satellite in circular orbit depends inversely on the orbital radius squared. If a statellite's orbital radius is four times that of another satellite, the further satellite experiences one-sixteenth the gravitational force that is exerted on the first satellite."arrow_forwardEvery few months, memes circulate claiming that certain alignments of the planets with the Earth will result in a change in the gravitational force you feel. Usually, these memes state that the alignment will counteract Earth's gravity slightly so you will feel less of a gravitational pull towards the Earth. Can this ever happen? Let's look at the numbers. What is the gravitational force (in N) of the Earth on you (ME = 5.97 ✕ 1024 kg, RE = 6380 km)? Say your mass is 68 kg. (Enter the magnitude.) What is the gravitational force (in N) of Jupiter on you when it is closest to Earth (MJ = 1.90 ✕ 1027 kg, RJE = 5.88 ✕ 108 km)? (Enter the magnitude.) By what factor would the mass of Jupiter need to increase to be equal to the gravitational force you feel from the Earth? Part 1 of 5 The gravitational force between two masses is given by Fg = −GMm r2 where G = 6.67 ✕ 10−11 m3/s2/kg. We can use this expression to determine the magnitude of the gravitational force you feel…arrow_forward
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage LearningPrinciples of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningCollege PhysicsPhysicsISBN:9781305952300Author:Raymond A. Serway, Chris VuillePublisher:Cengage Learning
- University Physics Volume 1PhysicsISBN:9781938168277Author:William Moebs, Samuel J. Ling, Jeff SannyPublisher:OpenStax - Rice University