University:
Acadia University
Course:
PHYS 1013 | Introductory Physics 1
Academic year:

2023
Views:

33

Pages:

7
Author:

esfredint7qo

Friction Purpose: The purpose of this experiment is to determine µs and µk and to understand static and kinetic friction. Theory: Static friction is a frictional force which resists force that is applied to a particular object. Hence the object stays at rest. The object only moves if the force of the static friction is overcome. For example, someone pushing a couch without it moving. If they push harder, it might overcome the static friction force and move. The coefficient of friction is µs. The equation of static friction is Fs ≤ µs x Fn where Fs = force of static friction in newtons (N), μs# = coefﬁcient of static friction and Fn# = normal force in newtons (N). The second type of frictional force is the kinetic friction. There is resistance to motion because of the object’s and surface’s contact. It acts in the opposite direction of motion. If someone is pushing an object forward, the friction pushes it backwards. Kinetic friction is only used when the object is moving. For example, pushing a box across a plank. The equation of kinetic friction is Fk ≤ µk x Fn where Fs = force of kinetic friction in newtons (N), μk# = coefﬁcient of kinetic friction and Fn# = normal force in newtons (N). Apparatus: 1. Extension spring with attached loop and carabiner, 2. Ruler, 30 cm, 3. Digital Scale, 4. Tape measure, 5. Plastic water bottle 0.5 liter, 6. Masking tape, 7. Letter size sheet of paper, 8. String. Data Collection: Calculations: Graph 1: spring extension vs pulling force from the data of spring calibration. Graph 2: static friction force vs the normal force. The µs from the slope is determined below. Graph 3: kinematic friction force vs the normal force. The µk from the slope is determined below. Discussion: We obtained the coefficient factor of static friction as 0.0008N and kinetic friction as 0.000656N. Errors in the experiment could have resulted due to many sources. A human error could be made while taking the measurements with the ruler. In the spring calibration experiment, the spring has to be stable and not bouncing to take the measurement which can be difficult. We can improve the accuracy of measurements by doing more trials.