What is the name given to a celestial object with a known brightness, used to establish distances in astronomy?

What is similar between metals and suspensions

In the united states, tornadoes generally occur because of the freezing of ocean water underwater earthquakes meeting of cool and warm air masses shifting of warm and cool ocean currents

Agust of wind pushes a beach ball with a force of 9 newtons.the ball rolls 10 meters in 3 seconds. what is the power of the wind?