On February 20, 1962, John Glenn became the first American to orbit Earth. If John Glenn weighed 640 N on Earth's surface,

a) how much would he
have weighed if his Mercury spacecraft had (hypothetically) remained
at twice the distance from the center of Earth?

b) Why is it said that an
astronaut is never truly "weightless?"

Calculate the mass of an object that has a momentum of 100kg x m/sec and velocity of 4 m/sec

Which accounts for an increase in the temperature of a gas that is kept a constant volume

Arunner is jogging at a steady 3.6 km/hr. when the runner is 2.9 km from the finish line, a bird begins flying from the runner to the finish line at 14.4 km/hr (4 times as fast as the runner). when the bird reaches the finish line, it turns around and flies back to the runner. even though the bird is a dodo, we will assume that it occupies only one point in space, i.e., a zero-length bird. how far does the bird travel? (b) after this first encounter, the bird then turns around and flies from the runner back to the finish line, turns around again and flies back to the runner. the bird repeats the back and forth trips until the runner reaches the finish line. how far does the bird travel from the beginning? (i.e. include the distance traveled to the first encounter)