Physics, 06.10.2019 03:50 queenpaige2015
Aroller coaster starts from rest at point a and continues to point b on a frictionless track. what best describes the changes in kinetic and potential energy as the car travels from point a to point b?
Answers: 2
Physics, 21.06.2019 22:40
The desk has a weight of 75 lb and a center of gravity at g. determine the initial acceleration of a desk when the man applies enough force f to overcome the static friction at a and b. also, find the vertical reactions on each of the two legs at a and at b. the coefficients of static and kinetic friction at a and b are ms = 0.5 and mk = 0.2, respectively
Answers: 2
Physics, 22.06.2019 00:00
A1000-kg weather rocket is launched straight up. the rocket motor provides a constant acceleration for 16-s, then the motor stops. the rocket altitude 20-s after launch is 510-m. you can ignore any effects of air resistance. a. what was the rocketâs acceleration during the first 16-s? b. what is the rocketâs speed as it passes through a cloud 5100-m above the ground?
Answers: 1
Physics, 22.06.2019 04:00
1. a student believes that colder water makes fish swim faster. he sets up an experiment using different temperatures of water and measures the speed of the fish. (chapter 1 â page 9) a. what is the independent variable? b. what is the dependent variable? c. list two constants the student should have for this experiment. 2. convert 0.375 mg to grams. show your work with units in order to receive credit. (chapter 1 â page 16) 3. a race car drives one lap around a race track that is 500 meters in length. (chapter 2 â pages 45-46) a. what is the driverâs displacement at the end of the lap? b. how is his displacement different from the distance traveled? 4. how far does a car travel in 90 seconds if it is traveling at a speed of 55 m/s? show the appropriate equation from your textbook and show your work with units in order to receive credit. (chapter 2 â pages 46-47) 5. two cars, both with a mass of 500 kg, are traveling down a road. the first car has a velocity of 65 m/s east and the second car has a velocity of 85 m/s west. (chapter 2 â pages 54-55) a. calculate the momentum of both cars showing the appropriate equation from your textbook and your work with units in order to receive credit. b. which car has the larger momentum? explain how you know. 6. an airplane traveling at 60 m/s comes to a stop in 10 seconds. calculate the airplaneâs acceleration. show the appropriate formula and show your work with units in order to receive credit. (chapter 2 â pages 57-58) 7. an individual has a weight of 735 newtons. what is the individualâs mass? show the appropriate equation from your book and show your work with the units in order to receive credit. (chapter 3 â pages 78-79) 8. in terms of newtonâs first law of motion, explain why it is important to wear a seatbelt while riding in a car. (chapter 3 â page 86) 9. if you kick a tennis ball with 50 n of force and then kick a soccer ball with 50 n of force, explain the difference in their motion according to newtonâs second law. (chapter 3 â pages 81-82) 10. describe how the velocity and acceleration of a skydiver changes as she falls from the plane back to the ground. (chapter 3 â pages 88-89) 11. a child is swinging on swing. describe what happens to both the kinetic energy and potential energy of the child as she swings up and down. (chapter 4 â pages 123) 12. driving to work one morning, you get a flat tire. when using the car jack, you apply 120 n of force to the jack and the jack in turn applies 2000 n of force to lift the car up. what is the mechanical advantage of the jack? (chapter 4 â page 111) 13. a temperature of a 50 kg block increases by 15°c when 337,500 j of thermal energy are added to the block. (chapter 5 â pages 141-142) a. what is the specific heat of the object? show the appropriate equation from your book and show your work with units. b. what is the block made of? use the chart on page 141. c. is this block a good material for insulators or conductors? 14. explain why gases make better thermal insulators than solids or liquids. give one example from the textbook of a thermal insulator that can keep you warm on a cold day. (chapter 5 â pages 147) 15. several days after a snowfall, the roofs of some homes on your street have almost no snow on them, while the roofs on other homes are still snow covered. assuming they have all received the same amount of sunlight, give one reason for this observation related to thermal energy and insulation. 16. if you purchased a string of lights, how could you determine if the lights were wired in series or parallel? (chapter 6 â pages 185-186) 17. what happens to the current in a device if the resistance is decreased but the voltage stays the same? (chapter 6 â pages 181-182) 18. you measure the voltage difference of a circuit to be 15 v and the resistance to be 675 Ď. what is the current in the circuit? show the appropriate equation from your book and show your work with units. (chapter 6 â page 182) 19. explain why a magnet from your refrigerator could not be used to lift something as heavy as a car. (chapter 7 â pages 202-203)
Answers: 3
Physics, 22.06.2019 09:10
The air that we breath is made mostly of which gaseous molecule
Answers: 1
Aroller coaster starts from rest at point a and continues to point b on a frictionless track. what b...
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