If a diffuse gas of atoms is trapped, cooled, and compressed, the de Broglie wavelengths of some atoms can become larger than the distance between atoms. The overlap between atoms leads to new states of matter. In one experiment, 87Rb atoms were cooled to 20 nK. Required:
a. What is their de Broglie wavelength at this temperature?
b. How many times larger is this than the 0.47 nm diameter of the atoms?

Acar travels 40m in 8 seconds find the car speed

A5 foot by 5 foot box culvert is buried 6 feet beneath the surface of the ground. a crosssection of this very long culvert (into and out of the page) is illustrated below. assume that the soil in which the culvert is buried has the following properties: jt = 120 pcf, w = 12%, ko = 0.50, ka = 0.33, and kp = 3.00. calculate the total horizontal force per unit length of culvert (fh) felt on one of the vertical faces of the culvert.

An astronaut in space cannot use a scale or balance to weigh objects because there is no gravity. but she does have devices to measure distance and time accurately. she knows her own mass is 77.4 kg , but she is unsure of the mass of a large gas canister in the airless rocket. when this canister is approaching her at 3.50 m/s , she pushes against it, which slows it down to 1.30 m/s (but does not reverse it) and gives her a speed of 2.60 m/s . what is the mass of the canister?