Pls help it’s due today

Sort the images based on whether there's a force of attraction or repulsion between the magnets shown. attraction repulsion

An important dimensionless parameter concerned with very high-speed flow is the mach number, defined as v/c, where v is the speed of the object such as an airplane or projectile, and c is the speed of sound in the fluid surrounding the object. for a projectile traveling at 1170 mph through air at 50 ˚f and standard atmospheric pressure, what is the value of the mach number?

Which basic property determines a colored light's placement on the spectrum of visible light? a. speed b. frequency c. amplitude d. velocity