Give an example each of a useful physical change and chemical change. Explain how they are useful​

We put a force of 50n on an object and the acceleration is 100 m/s². what is the mass of the object?

The space between two 15-in.-long concentric cylinders is filled with glycerin (viscosity = 8.5 × 10-3 lb·s/ft2). the inner cylinder has a radius of 1 in. and the gap width between cylinders is 0.1 in. determine (a) the torque and (b) the power required to rotate the inner cylinder at 180 rev/min. the outer cylinder is fixed. assume the velocity distribution in the gap to be linear.

The energy produced as a result of this flow of electrons from atom to atom is called