Which two statements are true about a system? A: A system is a group of objects analyzed as one unit.
B: Energy that moves across system boundaries is conserved.
C: There’s only one way to define the boundaries of a system.
D: All systems are made by humans.

The sample with the lowest specific heat capacity will have the greatest temperature increase. in this case, it would be platinum.

Since the pully is a simple machine so the mechanical advantage is a 1

The answer is 4f======since electrostatic force is given by    we let f be the electrostatic force when  r = 1 m    if we let  denote the electrostatic force when the distance is decreased so that r = 0.5m, then    we established earlier that f = kq₁q₂. therefore    the force will now be 4f.