A plank 4 m long is used as an incline by raising one end 1 m. A 300-N block is to be pushed up the incline. Find the force parallel to the incline plane required to push the block up. The coefficient of

friction is 0.1.

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?