Be sure to answer all parts. in a future hydrogen-fuel economy, the cheapest source of h2 will certainly be water. it takes 467 kj to produce 1 mol of h atoms from water. what is the frequency, wavelength, and minimum energy of a photon that can free an h atom from water? enter your answers in scientific notation. frequency = 7.05 × 10 -32 s−1 wavelength = 4.26 × 10 -25 m minimum energy = × 10 kj/photon

Asheet of steel 1.5 mm thick has nitrogen atmospheres on both sides at 1200oc and is permitted to achieve a steady-state diffusion condition. the diffusion coefficient for nitrogen in steel at this temperature is 6 x 10- 11 m2 /s, and the diffusion flux is found to be 1.2 x 10-7 kg/m2 -s. also, it is known that the concentration of nitrogen in the steel at the high-pressure surface is 4 kg/m3 . how far into the sheet from this high-pressure side will the concentration be 2.0 kg/m3 ? assume a linear concentration profile.

What is the coefficient of kinetic friction μk between the block and the tabletop?

If a negatively charged particle is placed at rest in an electric potential field that increases in the positive x-direction, what will the particle do? a. accelerate in the positive x-direction b. remain at rest c. accelerate in the negative x-direction