FRICTION – IS THE FORCE RESISTING THE RELATIVEMOTION OF SOLID SURFACES, FLUID LAYERS, AND/ORMATERIAL ELEMENTS SLIDING AGAINST EACH OTHER. There are 5 types of friction: Dry friction- it resists relative lateral motion of solid surfaces (incontact). It is sub-divided into static and kinetic friction. Fluid friction- it describes the friction between layers within a stickyfluid that are moving relative to each other. Skin friction- it is the force resisting the motion of a solid body(through a fluid). Lubricated friction- it’s a case of fluid friction where a fluid separatestwo solid surfaces. Internal friction- it’s a force resisting motion between the elementsmaking up a solid material while it undergoes.
Friction is one of the important part of nature. It isnecessary for us, the frictional force act as a “naturalstopper” if a ball thrown on the ground go inany/specific direction it stops after sometime; it stopsbecause of frictional force acting on it. Friction can beused i n m a n y w a y s :- Due to friction no energy is destroyed (it act as a energy consumer). It is mostly used in converting kinetic energy into heatenergy. It is helpful for a person who is lost in a forest, it can beused to generate fire on a wood. Due to friction only we can write on a paper.
FORCES ARE ALSO DESCRIBED AS A PUSH OR PULL ON ANOBJECT. THEY CAN BE DUE TO PHENOMENA SUCH AS GRAVITY,MAGNETISM, OR ANYTHING THAT MIGHT CAUSE A MASS TOACCELERATE. SI UNIT OF FORCE IS NEWTON AND THE SYMBOL = F.Different types of forces are: Magnetic force Frictional force Gravitational force Electrostatic force Normal force
Magnetic force- It is the force that attracts iron towards itself. We can seemagnetic force in magnet kept near iron pins.Frictional force- Frictional force is the force that opposes motion between twosurfaces.Gravitational force- The force that acts on the objects and pulls the objectstowards earth (due to gravity).Electrostatic force- It is the force whichNormal force- It is a force that acts on an object experiencing 0 netforce, since his weight is balanced by a normal force exerted by theground.
Can you guess the followingforces: Which force is acting on the boy, after jump? Which force is acting on the rat ? If the person (who is cycling) stops paddling then, which force will act on the person and the bicycle?
Newton SI Dyne Kilo-pound Pound force Poundal unit 1N ≡ 1 kg · m/s² = 105 dyne ≈ 0.10197 kp ≈ 0.22481 lbF ≈ 7.2330 pdl1 dyne = 10−5 N ≡ 1 g·cm/s² ≈ 1.0197×10−6 kp ≈ 2.2481×10−6 lbF ≈ 7.2330×10−5 pdl 1 kp = 9.80665 N = 980665 dyne ≡ gn·(1 kg) ≈ 2.2046 lbF ≈ 70.932 pdl1 lbF ≈ 4.448222 N ≈ 444822 dyne ≈ 0.45359 kp ≡ gn·(1 lb) ≈ 32.174 pdl1 pdl ≈ 0.138255 N ≈ 13825 dyne ≈ 0.014098 kp ≈ 0.031081 lbF ≡ 1 lb·ft/s²
How do we measure force?We measure force by using an instrumentKnow as force meter (Newton meter). Force usually act in pairs. Force acts in a particular direction. We measure force in newtons.
We can’t always see the force. We sometimes feel the effects they have on things. The balloon in the picture is affected by forces.Forces can make things Forces can makespeed up. things slow down or stop.When you hit a tennis A parachute can make an objectball it speeds up. slow down because of air resistance.
Forces can make things change You can use a direction. spanner to slacken or tighten a nut. You can make a cricket ball change direction by hitting it with a bat. Forces can make things turn.Forces can makethings change shape.If you squeeze or kick a football, it Forces are every wherewill be compressed. !