is the . On a flat horizontal surface with no other vertical forces, 2. Types of Friction in Problems The Kirik methodology typically tests three distinct types:
: Occurs when a body rolls (e.g., a wheel); it is usually much smaller than sliding friction for the same materials. 3. Example Problems (Sufficient Level) fizika 7 klass kirik sila treniia dostatochnyi uroven
. What force is required to move the crate at a constant speed? : Calculate gravity force: Calculate friction: is the
At the "Sufficient Level," students are expected to move beyond simple definitions to applying formulas and understanding the physical relationships between variables. : Calculate gravity force: Calculate friction: At the
Note: For constant speed, the pulling force must equal the friction force. Task : To pull a sled at a constant speed, a force of is applied. Find the coefficient of friction. Solution : 4. Key Takeaways for Kirik's Methodology
: For sliding friction, the force is proportional to the normal force (weight on a horizontal surface): Ffr=μ⋅Ncap F sub f r end-sub equals mu center dot cap N Ffrcap F sub f r end-sub is the friction force (Newtons,