Explain how an astronaut in an orbiting satellite can use a spring with a known force constant to measure his mass. Normally he could hang motionless from the spring to stretch it and, thus, determine his weight mg from the force constant and the amount of stretch. By dividing his weight by g, he could determine his mass. This method will not work, however, since his apparent weight is zero.

Explain how an astronaut in an orbiting satellite can use a spring with a known force constant to measure his mass. Normally he could hang motionless from the spring to stretch it and, thus, determine his weight mg from the force constant and the amount of stretch. By dividing his weight by g, he could determine his mass. This method will not work, however, since his apparent weight is zero.