K Physics: How much work is done by friction on a sliding block?

In summary, work done by friction is the energy that is converted into heat when two surfaces rub against each other. It is calculated by multiplying the force of friction by the distance over which it is applied. The roughness of the surfaces, applied pressure, and speed can affect the amount of work done by friction. Friction can result in negative work, decreasing the total energy of the system. This can also impact the efficiency of machines by converting input energy into heat, which is not useful for work.
  • #1
DaRotot
3
0
A 2.3-kg block slides down a plane (inclined at 43degrees with the horizontal) at a constant speed of 3.3 m/s. At what rate is the frictional force doing work on the block?
 
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  • #2
The rate of doing work is just the power. Do you know an expression relating power and velocity? You'll also need the frictional force, but you should be able to get it because you're told that the block is traveling at a constant speed..
 
  • #3
..and also the work done will be negative , since the direction of the frictional force is opposite to the displacement direction.

BJ
 

1. What is work done by friction?

The work done by friction is the amount of energy that is converted into heat as a result of two surfaces rubbing against each other.

2. How is work done by friction calculated?

The work done by friction is calculated by multiplying the force of friction by the distance over which the force is applied.

3. What factors affect the amount of work done by friction?

The amount of work done by friction is affected by the roughness of the surfaces, the force of the applied pressure, and the speed at which the surfaces are moving.

4. Does friction always result in work being done?

No, friction can also result in negative work, meaning that it decreases the total energy of the system.

5. How does work done by friction impact the efficiency of machines?

The work done by friction can decrease the efficiency of machines by converting some of the input energy into heat, which is not useful for performing work.

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