What are the Differences between ancient and modern astronomy?

Groups of organs that work together to complete a process in the body are called: a. cells b. tissues c. nerves d. systems

Awave is produced in a rope. the wave has a speed of 33 m/s and a frequency of 22 hz. what wavelength is produced?

If two students are running down the hall toward each other, trying to get to class, and they have the same mass and acceleration, what will happen when they collide? will their forces cancel out or will each one experience a reaction?