When an astronaut in orbit experiences apparent weightlessness,
a. no forces act on the astronaut.
b. no gravitational forces act on the astronaut.
c. the net gravitational force on the astronaut is zero.
d. the net gravitational force on the astronaut is not balanced by a normal force.?

Apulley system is used to lift a 2,000 newton engine up a distance of 3 meters. the operator must apply a force of 250 newtons to the chain of the pulley system to lift the motor. to lift the engine 3 meters, the operator must pull a total of 30 meters of chain through the pulley system. what is the value of di?

The air that we breath is made mostly of which gaseous molecule

If a simple machine reduces the strength of a force, what must be increased?