What type of friction must you overcome to start an object moving?
static friction
Does kinetic friction speed up or slow down an object?
Does friction always slow things down? ANSWER: No! Kinetic friction does oppose the relative motion of two surfaces. If the one of these surfaces is stationary, then it will tend to slow down the moving object.
Which of the following will show maximum friction?
Sliding friction is maximum when both the surface rubbing against each other are rough, rather than when one of them is smooth or both are smooth. So a sand paper rubbing against a sand paper will have maximum friction.
What is ball bearing class 8?
Ball bearing is a device which consists of a ring of small metal balls. It is designed to make the moving parts of a machine to roll over each other rather than slide.
How do ball bearings reduce friction in Class 8?
Ball bearing reduce friction because they roll rather than slide. Because the balls are rolling they have a much lower coefficient of friction than if two flat surfaces were sliding against each other.
Why does ball bearings reduce friction?
In ball bearings, hard steel balls are fixed between the two cylinders. The two cylinders thus have smaller rolling friction instead of sliding friction. Hence ball bearings reduce friction because they roll rather than sliding producing rolling friction.
How are ball bearings useful to US Class 8?
Answer: A ball bearing works on the principle that rolling friction is less than sliding friction. It helps in reducing friction between two surfaces in contact and maintaining separation between the bearing races, thereby allowing minimal surface contact between two surfaces.
What is streamlining how it is useful?
How is it useful? Answer: Streamlining is a design that offers the least resistance to the flow of a fluid, especially air or water. Friction is minimum for a streamlined shape, which is rounded in the front and narrow at the back. It is useful as: Ship also have streamlined shapes to reduce friction with water.
What are lubricants How do they work for Class 8?
A substance that is introduced between two surfaces in contact, to reduce friction, is called a lubricant. Fluid friction can be minimized by giving suitable shapes to the objects moving in the fluids.