Finished experiment and now working on my PowerPoint. Here is my Research Paper:
This project was conducted to determine whether objects of different surfaces (but equally weighted) would travel similar distances as the surface is changed. The objective was to study how far objects would travel when the coefficient of Static or Kinetic friction changed across different surfaces. The effect of friction was investigated using four surfaces (fine finish wood, felt, aluminum foil,sandpaper, and Ice). Four objects were used: wood block, a small plastic container , eraser,and a sponge. The weight of each object was made similar by using coins or screws attached to the top or placed inside the object. Each object was shot across each surface five times for a total of 100 measurements, but knowing each distance will be different for the same object, take the average distance traveled. The starting point and force of the shooting mechanism were constant for each measurement. The distance traveled by the objects moving across the surfaces did not stay in the same relative order as the surfaces changed. The finished wood had the lowest friction effect since the objects traveled farther with a low coefficient of Friction. The least traveled distance was with sand paper and surprisingly enough the objects traveled about the same distance. My results indicated that coefficient of friction was dependent under different object-surface combinations, since many distances were not relative. The static friction needed for each object to move also varied with sandpaper needing more force to start moving it.Whenever anything moves, there's usually some form of friction trying to stop it. Friction is sometimes useful, at other times it's a problem. There are two types of friction: Static and Kinetic. Static friction is the initial force to get an object moving and anything lower than this limit will cause the object not to budge.”If we push the block harder and harder, the frictional force will increase, until it reaches a maximum. If we push harder still, the block will start to move, because we're now pushing harder than the frictional force.”(
Friction: Slowing things down) Static friction occurs when you rub two surfaces against each other. Even though you cant see it some surfaces are not all “smooth” and have some holes, cracks, or irregularities on the surface. Static Friction occurs because if there was no friction then any simple push could move the biggest and heaviest objects. If you try to slide two objects past each other, a small amount of force will result in no motion. The force of friction is greater than the applied force. Kinetic Friction on the other hand is the force that keeps the object in motion and is usually less than static friction because after the object “breaks free” of the static friction you need a little bit less to keep it in motion.”You do not need to apply quite as much force to keep the object sliding as you needed to originally break free of static friction.”(
Static and Kinetic Friction)The coefficient of both static and kinetic friction varies between different surfaces. What is the coefficient of friction? The level of friction that different materials exhibit. The coefficient can be measured using the formula µ = f / N, where µ is the coefficient of friction, f is the amount of force that resists motion, and N is the normal force. The force that resists motion can be found by using spring scales that are able to measure newtons of force. Normal Force is the force at which one surface is being pushed into another and can be identified by using the equation Fn = mg, mass times gravity.
Surface-on-Surface
Static µ
Kinetic µ
hook velcro-on-fuzzy velcro
>6.0
>5.9
avg tire-on-dry pavement
0.9
0.8
grooved tire-on-wet pavement
0.8
0.7
glass-on-glass
0.9
0.4
metal-on-metal (dry)
0.6
0.4
smooth tire-on-wet pavement
0.5
0.4
metal-on-metal (lubricated)
0.1
0.05
steel-on-ice
0.1
0.05
steel-on-Teflon
0.05
0.05
“You should keep in mind that it isn't possible to give accurate values for the coefficient of frictions due to changing surface smoothness. For example, not all pieces of metal have the same surface smoothness. Some that are highly polished may be more slippery than others that are pitted or scratched. These values are just meant to give you the approximate values.” (
The Force Friction).To summarize things up Friction is a force that is created whenever two surfaces move or try to move across each other. Friction always opposes the motion or attempted motion of one surface across another surface. Friction is dependant on the texture of both surfaces. Friction is also dependant on the amount of contact force pushing the two surfaces together. The force of static friction (fs) cancels out the applied force right up to and including when static friction reaches its maximum (fsmax). For applied forces greater than the maximum force of static friction the block starts to slip and then the value for friction becomes kinetic friction (fk) and the box is then under a net force so it accelerates to the right.
