Abinary star system in the constellation orion has an angular separation of 10-5 rad. if the wavelength of the light from the system is 500 nm, what is the smallest aperture (diameter) telescope that can just resolve two stars?

Idon’t quite understand this problem

Suppose you increase your walking speed from 7 m/s to 13 m/s in a period of 2 s. what is your acceleration?

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?