Find the coefficient of friction between block and surface

In summary, the coefficient of friction between a block and a surface can be determined by measuring the forces acting on the block when it is in motion or at rest. This involves using the formula \( \mu = \frac{F_f}{N} \), where \( \mu \) is the coefficient of friction, \( F_f \) is the force of friction, and \( N \) is the normal force. By conducting experiments to quantify these forces, one can calculate the frictional coefficient, which indicates how easily the block slides over the surface.
  • #1
shivu30198
1
0
Homework Statement
A block of mass 2.4 kg sliding along horizontal rough surface is traveling at a speed 4.1 m/s when strikes a massless spring and compresses spring a distance 3.7 cm before coming to stop. If the spring has stiffness constant 714.3 N/m, find coefficient of friction between block and surface.
Relevant Equations
Wfr= umgcos
Ff.x= mv2/2 - kx2/2
umgx= mv2/2-kx2/2
u= mv2-kx2/2mgx =
 
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  • #2
shivu30198 said:
Homework Statement: A block of mass 2.4 kg sliding along horizontal rough surface is traveling at a speed 4.1 m/s when strikes a massless spring and compresses spring a distance 3.7 cm before coming to stop. If the spring has stiffness constant 714.3 N/m, find coefficient of friction between block and surface.
Relevant Equations: Wfr= umgcos

Ff.x= mv2/2 - kx2/2
umgx= mv2/2-kx2/2
u= mv2-kx2/2mgx =
What is your question?

Also: please see LaTeX Guide to properly format your equations.
 
  • #3
Use energy conservation.
Since block comes to rest:
##(KE)_{initial}=\text{ Energy stored in spring }+\text{ Energy lost to friction } ##
 
  • #4
But you seem to know that, so are you asking us to do the mathematics?
 
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  • #5
shivu30198 said:
umgx= mv2/2-kx2/2
u= mv2-kx2/2mgx
Some mistakes in that last step.
 
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FAQ: Find the coefficient of friction between block and surface

1. What is the coefficient of friction?

The coefficient of friction is a dimensionless number that represents the ratio of the force of friction between two bodies and the force pressing them together. It quantifies how much frictional force is present compared to the normal force acting on the surfaces in contact.

2. How can I calculate the coefficient of friction between a block and a surface?

The coefficient of friction (μ) can be calculated using the formula: μ = F_f / F_n, where F_f is the force of friction and F_n is the normal force. You can measure the force required to move the block (F_f) and the weight of the block (which equals the normal force when on a flat surface) to find μ.

3. What factors affect the coefficient of friction?

The coefficient of friction is influenced by several factors, including the materials of the surfaces in contact, the roughness of the surfaces, the presence of lubricants, and environmental conditions such as temperature and humidity.

4. Is the coefficient of friction constant for all situations?

No, the coefficient of friction is not constant. It can vary depending on the conditions such as surface texture, the presence of contaminants (like oil or dirt), and the speed at which the surfaces are moving relative to each other. There are typically two coefficients: static (when objects are not moving) and kinetic (when objects are sliding against each other).

5. How can I experimentally determine the coefficient of friction?

To experimentally determine the coefficient of friction, you can perform a simple experiment where you place a block on a surface and gradually increase the angle of inclination until the block starts to slide. The tangent of the angle at which it begins to slide will give you the static coefficient of friction. Alternatively, you can measure the force required to move the block at a constant speed to find the kinetic coefficient of friction.

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