SCIENTIFIC WRITE UP
Static and Kinetic Friction
Caitlin Poxon
Aim
To prove that different masses of objects and angles of surfaces do not have an affect on the Friction co-efficient of certain surfaces but do have an affect on the static and kinetic frictional forces.
Investigative Question
Will different masses of an object and different angles of a surface have an affect on the surfaces friction co-efficient or just the static and kinetoic frictional forces?
Hypothesis
Changing the mass of an object to be moved or the angle of the surface it is on, will affect the static and kinetic forces required but will not influence the friction co-efficient of the surface.
Variables
Dependent: Static Friction, Kinetic Friction and Friction co-efficient.…show more content… Wooden block has an average kinetic friction of 1.2N on the counter, 2.1N on the desk and 1.3N on the concrete floor.
The co-efficient was different.
Experiment 1B:
Wooden block has an average static force of 2.28N with one silver mass disk (100g) on it, 2.3N with two silver mass disks (2x100g), 2,68N with three silver mass disks (3x100g), 2,58 with just the beige block (???) and 4,16 with all 4 weights on it.
Wooden block has an average kinetic friction of 1.45N with one silver mass disk (100g), 1.8N with two silver mass disks (2X100g), 2.16N with three silver mass disks (3x100g), 2.02N with beige block (???) and 3.2N with all 4 weights.
Co-efficient stayed roughly the same.
Experiment 1C:
Wooden block has an average static friction of 3.5N at a 30 degree angle and 4N at a 50 degree angle.
Wooden block has an average kinetic friction of 3n at a 30 degree angle and 3.5N at a 50 degree angle.
Results
SURFACES STATIC FRICTION (N) KINETIC FRICTION (N) Static
Co-efficient Kinetic Co-efficient
Counter 1.5 1.2 0.47 0.38
Wooden desk 3.1 2.1 0.97 0.66
Concrete floor 1.5 1.3 0.47 0.4
WEIGHTS(g) STATIC FRICTION (N) KINETIC FRICTION (N)…show more content… • Static Friction: the frictional force acting between two surfaces which are attempting to move but are not moving.
• Newton’s first law: when applying a force moving forward there must be a force pulling backwards to keep object from moving.
• Kinetic Friction: the frictional force acting between two surfaces which are in motion against each other.
• Static Friction increases with the force applied until it reaches maximum value.
• Kinetic Friction stays constant regardless of the applied force.
• Kinetic Friction has a smaller value than the maximum value of static friction.
Discussion
When completing the experiment, the spring balance had a Gravitational Force of 10N and not 9.8N. So the experiment was not accurate because of the 0.2N difference. Different people measured the Static and Kinetic Friction to make sure data collected was accurate.
Conclusion
Changing the mass of an object to be moved or the angle of the surface it is on, did affect the static and kinetic forces required but did no influence the Friction co-efficient of the object.
References
Website=Static and Kinetic Friction, ben_townsend, www.ffden-2.phys.uaf.edu, 05/03/2017 at