A tennis ball rolls at a constant speed down a ramp. When the tennis ball reaches the flat surface at the bottom of the ramp the speed of the ball
decreases (slows down). Which statement best explains why the speed of the
tennis ball decreases when it reaches the bottom? ​

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 least penetrating form of radiation is

The mass of the sun is 1.99×1030kg and its distance to the earth is 1.50×1011m. what is the gravitational force of the sun on the earth?