Laws of Motion 3 Flashcards
what is equilibrium
equilibrium of a systm of particles refers to a situation where the net external force acting on the system is 0. ( according to newton’s first law of motion, the body could either be in motion or in rest.)
what are concurrent forces
a number of forces acting at a point are caled concurrent forces
what are contact forces
a contact
force on an object arises due to contact with some
other object: solid or fluid.
what is normal reaction
it is the reaction force acting outward from the surface and perpendicular to it.
what is friction
it is the opposing force that is set up between the surfaces of contact when there is a relative motio between the two surfaces.
It is a self-adjusting force
It alway acts to the common tangent to the surfaces in contact
what is static friction
It the frction force when there is no relative motion between the bodies. It opposes the impending motion. It is alway greater than the contact force
what is kinetic friction
it is the friction force between the surfaces in cotact when the bodies are in motion. It opposes the actual relative motion.
wha is limiting friction
the max value of frictional force when the bodies in contact tend to have relative motion.
what is impending motion
Static friction opposes
impending motion. The term impending motion
means motion that would take place (but does
not actually take place) under the applied force,
if friction were absent.
what is friction dependent
friction static is independent of area of contact
friction kineitc is independent of area of contact. and nearly independent of velocity
what are the most common forces in mechanics
(i) Gravitational force
(ii)Normal reaction- perpendicular to the contact surface/plane
(iii) Tension- when a string is stretching it tries to go back to its original position. This restoring force is called as tension. It acts along the string away from body. Tension along a string is considered to tbe the same at all points when string is considered to be massless
(iv) Spring force- when a string is stretching it tires to restore its position, the restoring force is called as spring force. it is directly proportional to the extension of the string. F=-kx. its direction is along strong opp to the direction of extension.
Why is limtigng friction more than static and kinetic friction
More force is needed to overcome inertia of rest
What is banking of roads?
The phenomenon of raising the outer edge of a curved road above the inner edge is called as Banking of roads. It is more preferred because the horizontal component of normal reaction provides centripetal force in addition to frictional force
