A yau ma kamar kullum zamu kawo bayanai ne dangane da ilimin kimiyya da ya shafi physics, kuma za mu maida hankali ne akan motion, force da kuma friction.
Kamar yadda a baya cikin bayanan mu na baya akan kinematics da dynamics, mun ce shi KINEMATICS reshe ne na physics da yake lura da yadda motion yake aukuwa ko faruwa. A inda shi kuma DYNAMICS (shi ma reshe ne na physics) yake lura da yadda motion yake faruwa sa’annan kuma yana kokarin sanin abunda ya jawo aukuwan motion din. Abunda ake so dalibi ya sani a nan shi ne, ya iya gane kowani kalar motion sannan kuma ya san misalan su kamar yadda zamu kawo bayanai a cikin wannan makala.
Motion
Ita ‘motion’ tana karkashin kinematics ne, wanda kuma tana nufin ‘tafiya’ ko kuwa mu ce canjin guri da abu ke yi ta yadda ake lura da lokacin aukuwan canjin. A harshen Turanci zamu iya cewa motion is the change in position of a body with time with respect to a reference point. Or motion is the movement of a body from one point to the other. Ita motion tana aukuwa a dukkan naukan ‘matter’ (state of matter – solid, liquid and gas), kuma motion na kasancewa a yanayi daban-daban. Misalan motion suna nan kamar haka, movement of the earth round the sun, rotation of the sun about its axis, an aeroplane flying in/on the sky and a man walking or running.
Rabe-raben motion (types of motion)
Ita motion an kasa ta ne kamar haka;
- Random motion
- Translational motion
- Rotational motion
- Circular motion
- Oscillatory or vibratory motion
- Relative motion
Random motion: Wannan nau‘i na motion ba ya da “direction”, wato abun na tafiya ne a ko ta ina kawai, wani lokaci ana kiran wannan nau’in zig-zag motion. A Turance zamu iya kawo shi kamar haka random motion is the movement of a body in a zig-zag or disorderly manner with no specific direction. Misalan irin wannan motion sune; motion of dust particles in air, the motion of smoke particles da motion of butterfly da sauransu.
Translational motion: Wannan nau’in motion kuma shi ne idan mutum ko abu ya tafi straight babu kaucewa. A Turance zumu iya cewa is the type of motion whereby a body or an object moves in a straight line. It is also called rectilinear motion. Misalan wannan nau’in motion ga su kamar haka; walking from one wall of a class to the other but in a straight line, da kuma dropping of fruit from tree to the ground.
Rotational motion: Wannan shi ma wani nau’in motion ne dake faruwa idan tafiyan abu ya kasance yana FORMING CIRCLE ta yadda kuma abun zai kasance yana makale a guri guda. Muna iya kawo shi a Turance kamar haka; this type of motion occurs when a body moves in a circular path about its axis. Misalan sa na nan kamar haka; the rotation of the blades of fan, the rotation of a wheel about an axis, the rotation of the earth about its axis da sauransu.
Circular motion: Shi circular motion yana aukuwa ne idan asali dama akwai CIRCLE sai kuma abu ko mutum yazo ya zagaya shi CIRCLE din. A Turance zamu ce is a type of motion in which an object or a body moves round a circle and in this kind of motion the speed is constant. Misalin irin wannan nau’in motion sune, movevement of the earth round the sun, movement of a car around a round-about da sauransu.
Oscillatory or vibratory motion: A wannan irin motion kuma abun (wato object) yana tafiya gaba ne sa’annan sai kuma ya dawo baya, wato to and fro ko kuma abun ya tafi sama ya dawo kasa. A harshen Turanci kuwa zamu iya kawo shi kamar haka ‘this is the motion of a body in a to and fro manner about a fixed point’. When a body moves to and fro about a fixed point we say, the body is oscillating. Misalan su sune, motion of the balanced wheel of a wristwatch, motion of a simple pendulum, motion of a loaded test-tube inside water da sauransu.
Relative motion: Wannan irin motion yana faruwa ne idan mutum na tafiya a cikin mota sai ya ga kamar itatuwa ma suna tafiya. A Turance muna iya rubuta shi kamar haka, ‘relative motion is the motion of an object with respect to a reference point (mun yi bayani a baya akan reference point)
EXERCISE:
1. Write a short note on the following:
a) vibratory motion
b) translational or displacement motion
c) random motion.
2. Differentiate between rotational and circular motions.
3. mention three types of motion you know with at least one example each.
Causes and effects of motion
Sir Isaac Newton (wani masanin physics) ya yi bincike akan motion ta yadda ya gano cewa kowani abu (object) na kasancewa ne a gurin da aka ajjiye shi (wato state of rest –inertia). Idan ka ga ya bar gurin da yake akwai abunda ya sa shi barin gurin, sannan sai ya ce wannan abun kuma shine FORCE.
Kuna iya duba makalar mu da ta yi bayani akan yadda ake samo equation na motion da misalan yadda ake amfani da shi wajen amsa tambaya a physics.
Force
Shi kalmar force a fannin ilimin lissafi da fasaha, wato physics, na iya daukar ma’anar duk wani abu da ke iya sa wani abun ya tafi ko ya tsaya guri guda. Force, vector quantity ne domin yana da ‘MAGNITUDE AND DIRECTION’. A Turance zamu iya cewa, ‘force is the push or pull or is that which changes or tends to change the state of rest or a uniform motion of a body. Unit na force shi ne: NEWTON (N).
Types of force
Force iri biyu ne, ko ya kasance; contact force ko kuma field force. Contact force shi ne force dake existing, wato kasancewa, tsakanin bodies guda biyu da suke manne. Misalan sa sune friction, upthrust, reactional force, thrust, tension da sauransu.
Field force shi ma force ne dake existing sakanin bodies guda biyu amma wadanda basu manne ba ko basu tare. Misalansu su ne, electric force, magnetic force, gravitational force da nuclear force.
Friction: Force ne dake opposing relative motion kuma yana faruwa sakanin bodies ko abu guda biyu dake tare ko manne. Friction can be defined as the force that opposes the relative motion between any two bodies or surfaces in contact.
Shi ma friction ya rabu gida biyu, akwai dynamics friction da static ko limiting friction.
Static friction shi ne frictional force dake existing sakanin surfaces guda biyu kafun su fara tafiya ko kuma lokacin da zasu fara tafiya. Amma shi Dynamics frition, frictional force ne dake faruwa yayin da surfaces guda biyu suke cikin tafiya.
Laws of solid friction da kuma calculation akan friction
Laws of friction: Friction yana da laws guda biyar kamar yadda zamu gan su:
Na farko: friction is always opposing motion.
Na biyu: Friction depends on the nature of surfaces in contact. Abunda ake magana anan shi ne friction between two rough surfaces is greater than the frictional force between smooth surfaces.
Na uku: It does not depend on relative speed between the surfaces.
Na hudu: Friction does not depend on the area of the surfaces in contact. Sai kuma na karshe
Na biyar: Frictional force is directly proportional to the normal reaction(R) between the two surfaces in contact. A nan zamu iya rubuta shi mathematically kamar haka
F α R 1
F = µR 2
Ta yadda F = Frictional force, R= Normal reaction da µ ana kiransa coefficient of friction wannda constant ne.
Sannan ana iya rubuta R = mg 3
Ta yadda m = mass na body, g = acceleration due to gravity.
Kafin ku yi exercise din idan kuna so kuna iya duba makalarmu da ta yi bayani akan banbancin dake tsakanin mass and weight, dimension, position, distance and displacement.
EXERCISE
- Define force
- Mention the two types of force and give two example each.
- Mention three laws of friction you know.
Tambaya ta farko: A crate slide down an inclined plane such that the frictional force opposing its motion is 40N. If the normal reaction of the plane on the crate is 50N, calculate the coefficient of dynamics friction.
Solution: A nan zamu ga an bamu F = 40N, R = 50N sai kuma aka ce mu samo µ =? Fomular da ta kamata mu yi amfani da ita, ita ce:
F = µR Idan muka ce a raba kowane gefe da R, zamu samu µ = = = = 0.8
Shi coefficient of friction bai da units haka za a bar shi.
Tambaya ta biyu: A block of mass 12kg rests on a horizontal floor, the coefficient of friction is 0.35. Determine the minimum force required to move the block when pulling horizontally (take g = 10ms ).
Solution: Wannan tambayar kuma zamu gani an bamu mass m = 12kg, g =10ms , µ = 0.35 kuma ana neman F =? Da Farko zamu fara nemo R sannan daga karshe mu samo F din.
R = mg = 12 10 = 120N dama kuma mun san
F = µR = 0.35 120 = 42N.