Physics, 25.11.2021 14:00 dorothybean
You and two friends are planning on lifting a 3.25 kN piano at constant speed to your apartment 26.0 m above the street level using a pulley system fastened to the roof of the building. Each of you is able to deliver energy at the rate of 160 W by doing work on the rope of a pulley system that is 75.0% efficient. That is, 25.0% of the energy is transformed to other forms due to friction in the pulley. You wish to block off the sidewalk to protect pedestrians while you raise the piano, but are worried because it is a busy street and you may get in trouble with local authorities if you block the sidewalk too long. For what time interval (in min) will the sidewalk be blocked while the piano is moving upward
Answers: 1
Physics, 23.06.2019 01:10
The path of a satellite orbiting the earth causes it to pass directly over two tracking stations a and b, which are 51 miles apart. when the satellite is on one side of the two stations, the angles of elevation at a and b are measured to be 87 degrees and 84 degrees, respectively. (a) how far is the satellite from station a? (b) how high is the satellite above the ground?
Answers: 3
Physics, 23.06.2019 08:00
All phase changes are .an example of a phase change is an ice cube melting
Answers: 2
Physics, 23.06.2019 11:30
Which of the following characteristics of earth's relationship to the sun explains the existence of earth's seasons? choose all that apply. earth has a satellite called the moon, which rotates around earth. earth spins on its axis, completing one rotation each day. earth's axis always points in the same direction relative to the stars. earth's axis is tilted relative to its orbital plane. earth orbits around the sun, completing one orbit each year.
Answers: 1
Physics, 23.06.2019 11:50
Which of the following best explains what happens when the kinetic energy of particles in a liquid state decreases?
Answers: 2
You and two friends are planning on lifting a 3.25 kN piano at constant speed to your apartment 26.0...
Chemistry, 31.05.2021 14:00
Mathematics, 31.05.2021 14:00
Computers and Technology, 31.05.2021 14:00
Mathematics, 31.05.2021 14:00
English, 31.05.2021 14:00
Computers and Technology, 31.05.2021 14:00
Biology, 31.05.2021 14:00
World Languages, 31.05.2021 14:00
Mathematics, 31.05.2021 14:00
Social Studies, 31.05.2021 14:00
Spanish, 31.05.2021 14:00
Mathematics, 31.05.2021 14:00
Computers and Technology, 31.05.2021 14:00
Computers and Technology, 31.05.2021 14:00