What is the weight of a 40kg object on the moon ? (in newtons)

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.

The receptor cells that convert light energy into neural signals are called

Aspring that is stretched 2.6 cm stores a potential energy of 0.053 j. what is the spring constant of this spring?