Friction is the force that opposes the motion of an object. When we push an object with only a small amount of force, it does not move at all. It means that the surface on which the object is resting applies some force on the object and the force is acting in a direction opposite to the force of our push this force is knwon as Friction.

eg: A ball moving on the ground slows down or stops due to the friction between the ball and ground.

Cause of Friction

Whenever we see the surface of any object through microscope it always have some rough patches, even though if it looks like smooth with naked eyes. When the rough patches of two surfaces moves over each other they get locked. The interlocking of two surfaces opposes the motion of one body over another and gives rise to frictional force.

Laws of Friction

The four important laws of friction are as follows:

  1. Friction opposes the motion
  2. Friction is independent of the area of contact between the two surfaces
  3. Friction depends on the nature of the two surfaces in contact. In other words, firction depends on the kind of materials, smoothness and degree of lubrication.
  4. Fractional force is directly proportional to the weight of the body which tends to move. This is why it is difficult to move heavier objects


Types of Friction

Maily the friction is of three types:

  1. Static Friction: It is the friction exerted on a object at rest. Station friction is also known as limiting friction
  2. Sliding Friction: Sliding friction is slightly less then the static friction. It is exerted when an object slides over a surface. Sliding friction is also known as dynamic friction or kinetic friction.
  3. Rolling Friction: It is the friction exerted when an object rolls over a surgace.Rolling friction is always less then the sliding friction and static friction.


Methods of Reducing Friction

Friction is caused due to the roughness of surface. Any process by which we can make the two surfaces smooth will reduce the fiction. Some commonly used methods for reducing friction are:

  1. By polishing
  2. By applying lubricants(oil or greese)
  3. By using ball-bearings
  4. By using rolars and wheels

Latest Current Affaris

Current affairs 05/06/2019
Current affairs 05/06/2019

1). Comptroller and auditor general Rajiv Mehrishi has been appointed as the external auditors of World Health Organisation (WHO) for a four year term from 2020-23. 2).World Environment Day is observed on 5 June(Theme: The Air Pollution). 3). Madhya Pradesh cabinet has passed a resolution to increase reservation of OBC's 27%.

करंट अफेयर्स 03-04/06/2019
करंट अफेयर्स 03-04/06/2019

1. नयब बुकेले को ईआई सल्वाडोर के राष्ट्रपति के रूप में चुना गया है। (ईआई सल्वाडोर की राजधानी: सैन सल्वाडोर, मुद्रा: संयुक्त राज्य अमेरिका डॉलर) 2. राष्ट्रीय सुरक्षा सलाहकार (NSA) अजीत डोभाल की दोबारा अपने पद पर नियुक्ति हुई। NDA सरकार के दूसरे कार्यकाल में उन्हें कैबिनेट रैंक दिया गया है। 3. 3 जून को विश्व साइकिल दिवस मनाया जाता है।

Current affairs 03-04/06/2019
Current affairs 03-04/06/2019

1. Nyaib Bukele has been Sworn in as the president of  EI Salvador ( EI Salvador's capital: San Salvador, currency: United States Dollar). 2. National Security Advisor (NSA) Ajit Doval reappointed to his post and given Cabinet rank in the second term of the NDA government. 3. World Bicycle Day is observed on 3rd June .

Current Affairs Quiz

डेली जीके क्विज 17/05/2019
डेली जीके क्विज 17/05/2019

1. भारतीय नौसेना प्रमुख का नाम बताएं? 2. हाल ही में ICC द्वारा पहली महिला मैच रेफरी के रूप में किसे नियुक्त किया गया है? 3. हाल ही में एक हल्के खेल विमान (एलएसए) में अटलांटिक महासागर को पार करने वाली दुनिया की पहली महिला कौन बनी है?

Daily Gk Quiz 17/05/2019
Daily Gk Quiz 17/05/2019

1. Name the Indian Navy Chief? 2. Recently who has been appointed as first female match referee by ICC? 3. Recently who has becomes the world’s first woman to cross the Atlantic Ocean solo in a light sports aircraft (LSA)?

डेली जीके क्विज 29/09/2018
डेली जीके क्विज 29/09/2018

प्रश्न 1)। हाल ही में एशियाई विकास बैंक (एडीबी) ने राज्य में रोजगार को बढ़ावा देने के लिए मध्य प्रदेश में पहला बहु-कौशल पार्क स्थापित करने के लिए 150 मिलियन डॉलर के ऋण को मंजूरी दे दी है। एडीबी के अध्यक्ष कौन हैं? प्रश्न 2)। परकर्म परव किस अवसर पर मनाया जा रहा है? प्रश्न 3)। भारत की लाइव स्टॉक जनगणना 1 अक्टूबर से शुरू होने वाली है। इस तरह की कितनी जनगणना पहले आयोजित की गई है और यह कौन सी जनगणना है?