1. A 55 kg man runs up the stairs below in 5 seconds. How many watts of power did he use? 2. A 55 kg man runs up the stairs below in 5 seconds. How can he reduce the power he uses?

The speed of light in a material is 0.50 c. what is the critical angle of a light ray at the interface between the material and a vacuum?

Aball has an initial velocity of 3 m/s. if there is no friction, what is the highest it could roll?

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?