What does compressional mean in waves

Which terms describe the purpose of antennas on devices that use radio waves? transmit and receivemodify and amplifyamplify and receivemodify and transmit

Two students, each riding bicycles, start from the same apartment building and ride to the same building on campus, but each takes a different route. the first student rides 1100 m due east and then turns due north and travels another 1430 m before arriving at the destination. the second student heads due north for 1930 m and then turns and heads directly toward the destination.at the turning point, how far is the second student from the destination?

Heterogeneous mixture with larger particles that never settle is