Question

Match List I with List II from the combinations below

List I	List II
a. nonconservative froce	e. depends on mass
b. conservative force	f. work done independent of path
c. deceleration due to friction on rough horizontal surface	g. work done depends on path
d. accelerating force on a smooth inclined surface	h. independent of mass

The correct match is

• A. $a\to g;b\to h;c\to f;d\to e$
• B. $a\to f;b\to e;c\to h;d\to g$
• C. $a\to g;b\to f;c\to h;d\to e$
• D. $a\to e;b\to g;c\to h;d\to f$

Answer 1

Answer: (C)

$a\to g;b\to f;c\to h;d\to e$

It is not always true that the work done by an external force is stored as some form of potential energy. This is only true if the force is conservative. The work a conservative force does on an object in moving it from one end to other is path independent - it depends only on the end points of the motion. Examples: the force of gravity and the spring force are conservative forces. For a non-conservative (or dissipative) force, the work done in going from one end to other depends on the path taken. Examples: friction and air resistance.
Accelerating force on a smooth inclined surface proportionally increases with the mass of the body. But deceleration due to friction on rough horizontal surface is independent of mass. As in this case frictional force and weight of the mass act perpendicularly.