It is interesting to speculate on the properties of a universe with different values for the fundamental constants.
a. in a universe in which planck’s constant had the value h = 1 j s, what would be the de broglie wavelength of a 145 g baseball moving at a speed of 20 m/s?
b. suppose the velocity of the ball from part (a) is known to lie between 19 and 21 m/s. what is the smallest distance within which it can be know to lie?
c. suppose that in this universe the mass of the electron is 1 g and the charge on the electron is 1 c. calculate the bohr radius of the hydrogen atom in this universe

Why is alchemy not considered to be a science ?

After the near spacecraft passed mathilde, on several occasions rocket propellant was expelled to adjust the spacecraft's momentum in order to follow a path that would approach the asteroid eros, the final destination for the mission. after getting close to eros, further small adjustments made the momentum just right to give a circular orbit of radius 45 km (45 × 10^3 m) around the asteroid. so much propellant had been used that the final mass of the spacecraft while in circular orbit around eros was only 545 kg. the spacecraft took 1.04 days to make one complete circular orbit around eros. calculate what the mass of eros must be.

Abeam of electrons with of wavelength of 7.5 x 10-6 m is incident on a pair of narrow rectangular slits separated by 0.75 mm. the resulting interference pattern is projected onto a screen 10.0 m from the slits. what is the separation of the interference maxima in the resulting interference pattern?