A feather (mass = 0.1kg) and a bowling ball (4.5kg) will both fall at the SAME rate on Earth (g=9.8m/s2) if there is no air resistance. How much force does each item have if it is falling due to the acceleration of gravity?

Which is not a source of noise pollution? a)airplanes b)acid rain c)machines d)cars

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.

Engineers find a new metal that is stronger than steel but much lighter. this material is also significantly cheaper than what is currently used for most aircraft, available in large quantities, and easy to manufacture. the engineers are excited because this new material will lower the costs of buying and operating airplanes for companies. what is probably the best step for the engineers to make next?