Julia rides her horse 12 miles in 45 minutes. what is her average speed in mi/min?

Describe how the fermi level changes with donor level, temperature and contact with p and n type semiconductors

A20 cm long spring is attached to a wall. the spring stretches to a length of 22 cm when you pull on it with a force of 100 n. what is the spring constant

The horizontal blue line through the middle of the lens is called the optical axis. as the lamp is moved above or below the axis, keeping the horizontal distance to the center of the lens constant, how does the horizontal distance from the lens to the image change?