Why does alpha centauri appear to be yellow-white?

Which quantities are scalars? choose all that apply a.distance b.speed c. acceleration d.velocity

An object moves from position +34m to the position -15m in 15 seconds. what is the total displacement? what is the total velocity?

Carbon is allowed to diffuse through a steel plate 15 mm thick. the concentrations of carbon at the two faces are 0.65 and 0.30 kg c/m^3 fe, which are maintained constant. if the preexponential and activation energy are 6.2 x 10-7 m2 /s and 80,000 j/mol, respectively, compute the temperature at which the diffusion flux is 1.43 x 10^-9 kg/m^2 -s.