Suppose astronomers discover a radio message from a civilization whose planet orbits a star 35 light-years away. their message encourages us to send a radio answer, which we decide to do. suppose our governing bodies take 2 years to decide whether and how to answer. when our answer arrives there, their governing bodies also take two of our years to frame an answer to us. how long after we get their first message can we hope to get their reply to ours? (a question for further thinking: once communication gets going, should we continue to wait for a reply before we send the next message? )

Select all that applywhat are some basic resources a family is expected to provide for children? educationclothesspending

As part of your daily workout, you lie on your back and push with your feet against a platform attached to two stiff springs arranged side by side so that they are parallel to each other. when you push the platform, you compress the springs. you do an amount of work of 79.0 j when you compress the springs a distance of 0.230 m from their uncompressed length. (a) what magnitude of force must you apply to hold the platform in this position? (b)how much additional work must you do to move the platform a distance 0.230 m farther? (c) what maximum force must you apply to move the platform a distance 0.230 m farther?

Which of the following best describes internal energy? a. the difference between the kinetic and potential energies of the particles in a system b. the sum of the kinetic and potential energies of the particles in a system c. the sum of the kinetic and thermal energies of the particles in a system d. the difference between the kinetic and thermal energies of the particles in a system