A 500 g block lies on a horizontal tabletop. The coefficient of kinetic friction between the block and the surface is 0.25. The block is connected by a massless string to the second block with a mass of 300 g.
The string passes over a light frictionless pulley as shown above. The system is released from rest.
Find the acceleration of the system by simultaneously solving the system of two equations.
What is the tension force in the string?

Ascientist is working with a new kind of quantum dot to make a dye. he is applying newton’s laws to the particle, but it seems to be breaking these laws of physics. which action will most likely the scientist study the particle’s motion? a. he needs to remember that the particle is too large for quantum analysis. b. he must continue to use newtonian mechanics, but he needs to learn more about the particle. c. he needs to use quantum mechanics, not newtonian mechanics, because this is a nanotechnology product. d. he must determine new physical laws that only apply to quantum dots.