To simulate the apparent weightlessness of space orbit, astronauts are trained in the hold of a cargo aircraft that is accelerating downward at g. Why do they appear to be weightless, as measured by standing on a bathroom scale, in this accelerated frame of reference? Is there any difference between their apparent weightlessness in orbit and in the aircraft?

We will see that Newton's laws of classical physics apply only in certain "inertial" frames of reference.  As an example, consider being in an airplane on a long trans-Pacific flight.  It is dark, the shades are drawn, and all of your fellow passengers are quietly asleep, watching movies, or reading.  You however, being a newly trained physicist, want to do an experiment to see how fast the plane is flying. With the tools you have (no GPS!) which one of the following is true.     If you toss something to a friend down the aisle, and they toss it back to you, there will be a difference in the speeds in the two directions because of the speed of the airplane.     Look at the tip of the coffee's liquid surface in your cup. It tips more the faster you go.     There is no experiment we can do.      Drop something.  It will not fall straight down because the plane is moving On a plane flat surface with "up" given as  +y and  "right" given as +x, we add two…

An 80.0-kg astronaut in a spaceship above Earth has a weight of 657 N.(a) What is the value of g at the astronaut’s location?(b) What is the distance of the astronaut from the centre of Earth?

Suppose that a mass m is located at the origin (Oi+0j). What is the total force due to gravity exerted on the mass by two other masses: 5m at a position of yj, and 4m at a position of xi. Express your answer in vector notation (i and j).