Your friends says the helium in your birthday helium comes from radioactive decays. what is your response?

Anton created a chart listing different types of materials. which best complete the chart? (a)x: copper y: glass(b)x: rubber y: copper(c)x: paper y: silicon(d)x: silicon y: glass

Discuss how the hardness or softness of the landing surface is related to the time required to stop the egg

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?