Which type of waves give scientists information about the structure of Earth's interior layers?

An object moves from position +34m to the position -15m in 15 seconds. what is the total displacement? what is the total velocity?

What is the name of the perceived change in a sound wave’s frequency due to motion between the observer and the sound source?

Ablue car pulls away from a red stop-light just after it has turned green with a constant acceleration of 0.5 m/s 2 . a green car arrives at the position of the stop-light 6.5 s after the light had turned green. if t = 0 when the light turns green, at what time does the green car catch the blue car if the green car maintains the slowest constant speed necessary to catch up to the blue car? answer in units of s.