1. Force is a vector quantity that can change the state of motion or shape of an object.
  2. The SI unit of force is the newton (N).
  3. Force is classified into contact forces (e.g., friction, tension) and non-contact forces (e.g., gravitational, electrostatic).
  4. Friction is the resisting force that opposes the motion or tendency of motion between two surfaces in contact.
  5. The direction of frictional force is always opposite to the direction of motion.
  6. Friction is caused by the interlocking of surface irregularities and intermolecular forces between surfaces.
  7. Static friction prevents an object from starting to move and acts when the object is at rest.
  8. The maximum force of static friction is called the limiting friction.
  9. Kinetic friction, also known as sliding friction, acts when an object is in motion.
  10. Rolling friction is the resistance faced by an object rolling over a surface and is much smaller than static or kinetic friction.
  11. The coefficient of friction (μ) is the ratio of the force of friction to the normal force.
  12. Static coefficient of friction (μs) is generally higher than the kinetic coefficient of friction (μk).
  13. The formula for the maximum static friction is F = μsN, where N is the normal force.
  14. The formula for kinetic friction is F = μkN.
  15. Normal force is the perpendicular contact force exerted by a surface on an object resting on it.
  16. Air resistance and fluid friction are forms of friction that occur in fluids (liquids and gases).
  17. Friction converts mechanical energy into heat, causing energy dissipation.
  18. Advantages of friction include aiding in walking, gripping objects, and braking in vehicles.
  19. Disadvantages of friction include wear and tear of machinery and loss of energy.
  20. Lubricants are used to reduce friction between moving parts of machinery.
  21. Ball bearings reduce friction by converting sliding motion into rolling motion.
  22. Friction depends on the nature of surfaces and the normal force, but not on the area of contact.
  23. Newton’s First Law relates to friction by explaining how objects tend to stay in their state of rest or motion unless acted upon by an external force.
  24. In inclined planes, friction opposes the component of weight acting parallel to the surface.
  25. The angle of repose is the maximum angle of an inclined plane at which an object remains stationary due to friction.
  26. Dynamic friction includes both sliding and rolling friction.
  27. Fluid friction, or drag, increases with the velocity of an object moving through a fluid.
  28. Streamlining reduces fluid friction by minimizing the resistance offered by the fluid.
  29. The force of friction can be calculated using free-body diagrams and equilibrium equations.
  30. Sliding friction is always less than or equal to static friction for the same surfaces.
  31. Frictional forces are crucial for maintaining traction in vehicles and avoiding skidding.
  32. Friction is independent of the relative velocity between surfaces for small speeds.
  33. The work done against friction is converted into heat energy.
  34. Adhesion at the molecular level contributes significantly to friction.
  35. Friction plays a key role in enabling objects to accelerate, decelerate, or turn.
  36. Devices like anti-lock braking systems (ABS) use the principles of friction for safety.
  37. Frictional force can be experimentally measured using a spring balance.
  38. Wear and tear caused by friction can be minimized by proper lubrication and surface treatments.
  39. Static friction has a self-adjusting nature, increasing to counter external forces up to a limit.
  40. Friction in real-life applications includes walking, driving, and gripping objects securely.
  41. Wheels and rollers are used to reduce friction in transportation systems.
  42. Frictional force is proportional to the weight of the object, as weight affects the normal force.
  43. Frictional heating is utilized in applications like matchstick ignition and vehicle braking.
  44. Excessive friction can lead to energy losses in mechanical systems.
  45. Static equilibrium on inclined planes is determined by balancing frictional and parallel forces.

Category

Questions

  1. What is friction?
  2. Which type of friction acts on a stationary object?
  3. What is the SI unit of force?
  4. What does the coefficient of friction depend on?
  5. Which of the following is an example of kinetic friction?
  6. What type of force is friction?
  7. Which frictional force is the smallest?
  8. What happens to friction if the weight of an object increases?
  9. What is the limiting friction?
  10. Which type of friction acts when an object is moving through air?
  11. Which factor does not affect friction?
  12. Why is friction considered a necessary evil?
  13. What type of friction acts on a ball rolling on a surface?
  14. How can friction be reduced?
  15. What is the angle of repose?
  16. Which force resists the motion of an object through a fluid?
  17. What is the main cause of friction?
  18. What is the relation between frictional force and normal force?
  19. What type of friction occurs when two surfaces are in relative motion?
  20. What is the coefficient of static friction for a frictionless surface?
  21. Which of the following is not a method to reduce friction?
  22. Why does a rougher surface have more friction?
  23. What happens to friction when the surface area increases for the same weight?
  24. What type of friction acts just before an object starts moving?
  25. Which force is responsible for wear and tear in machines?
  26. Why are cars fitted with tires having tread patterns?
  27. What is the function of lubricants?
  28. Why does friction generate heat?
  29. What is the direction of frictional force relative to motion?
  30. Which of the following increases friction?
  31. Why is rolling friction less than sliding friction?
  32. What is the coefficient of kinetic friction?
  33. Which type of friction is encountered while walking?
  34. How does friction affect the efficiency of machines?
  35. Why do athletes use spikes in their shoes?
  36. Which of the following is an example of fluid friction?
  37. Which law states that friction is independent of the apparent area of contact?
  38. Why do objects eventually stop moving on rough surfaces?