subject

Friction

Physics ⇒ Mechanics

Friction starts at 8 and continues till grade 12. QuestionsToday has an evolving set of questions to continuously challenge students so that their knowledge grows in Friction. How you perform is determined by your score and the time you take. When you play a quiz, your answers are evaluated in concept instead of actual words and definitions used.
See sample questions for grade 11
A 10 kg box rests on a horizontal surface. If the coefficient of static friction is 0.4, what is the maximum static friction force that can act on the box? (Take g = 9.8 m/s²)
A 2 kg object is placed on a rough horizontal surface. If the coefficient of static friction is 0.5, what is the maximum horizontal force that can be applied before the object starts to move? (Take g = 10 m/s²)
A 20 kg crate is at rest on a horizontal floor. The coefficient of static friction is 0.3. What is the minimum force required to just start moving the crate? (Take g = 9.8 m/s²)
A 50 kg box is pulled with a force of 200 N on a horizontal surface. If the coefficient of kinetic friction is 0.3, what is the acceleration of the box? (Take g = 10 m/s²)
A block is sliding down an inclined plane with a constant velocity. What can you say about the net force acting on the block?
A car of mass 1000 kg is moving on a road with a coefficient of friction 0.6. What is the maximum possible frictional force between the tires and the road? (Take g = 10 m/s²)
A force of 15 N is required to move a 3 kg block at constant speed across a horizontal surface. What is the coefficient of kinetic friction? (Take g = 10 m/s²)
Describe one advantage and one disadvantage of friction in daily life.
Explain why ball bearings are used in machines.
Explain why it is difficult to walk on a smooth, icy surface.
Explain why the frictional force is less when a body is moving compared to when it is just about to move.
If the normal reaction between two surfaces is doubled, what happens to the frictional force?
State the difference between static friction and kinetic friction.
The coefficient of kinetic friction between a box and the floor is 0.2. If the box has a mass of 5 kg, what is the force required to keep it moving at constant speed? (Take g = 10 m/s²)
Which law states that the force of friction is independent of the area of contact between two surfaces?