A 10 Kg object hangs at rest from a spring with force constant 180 N/m. A 15 Kg object is gently placed on the 10 Kg object, and released from rest from the initial position. (The objects stick together) 00000000 10 kg 180 N/m 15 kg

1 2 3 4 31 5 A 1.0 kg block is connected to a horizontal spring as shown with spring constant 200 N/m. You pull the block horizontally, stretching the spring a total of 20 cm from its equilibrium position. The kinetic frictional coefficient between the surface and the block is 0.25. What is the acceleration of the spring right after you let go of it? (b) 0 0 0 0 37.62 42.5 40 m 58.12 www Fspr x = 0 ↑

The graph shows the measured force for a spring as it is compressed through various displacements.

How do you measure the mass of an astronaut in orbit? (You can't just use a scale!) For the 1973 - 1979 Skylab program (Skylab was a space station that predated the current International Space Station), NASA engineers designed a Body Mass Measuring Device (BMMD). This is essentially a chair of mass m mounted on a spring with a carefully measured spring constant ks = 605.6 N/m. (The other end of the spring is connected to the Skylab itself, which has a mass much larger than the astronaut or the chair, and so remains essentially fixed as the astronaut oscillates.) The period of oscillation of the empty chair is measured to be 0.90149 s. When an astronaut is sitting in the chair, the period is 2.12151 s. What is the astronaut's mass? Please describe your reasoning!