If an object's velocity changes from 25 meters per second to 15 meters per second in 2.0 seconds, the magnitude of the
object's acceleration is
A 5.0 m/s2
B 7.5 m/s2
C 13 m/s2
D 20 m/s2

Determine the maximum r-value of the polar equation r =3+3 cos 0

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.

What component of earth’s atmosphere exists entirely as a result of photosynthesis?