Thread: phisics, coefficient of static friction

1. phisics, coefficient of static friction

i think it involves the pythagorem theorem but not really sure how to apply it. any help would be much appreciated.

"Mass of wood block without any weight = 5.0 kg; g = 9.8 m/s2"

"It was observed that the spring scale reached a force of 24.0 N to get the block moving from rest. Calculate the coefficient of static friction between the wood block and the table."

2. Originally Posted by 14041471
i think it involves the pythagorem theorem but not really sure how to apply it. any help would be much appreciated.

"Mass of wood block without any weight = 5.0 kg; g = 9.8 m/s2"

"It was observed that the spring scale reached a force of 24.0 N to get the block moving from rest. Calculate the coefficient of static friction between the wood block and the table."
is the block on a horizontal surface?

is the applied force parallel to the surface on which the block rests?

"A block of wood is dragged across a surface by a spring scale. The scale records the force as mass is added to the top of the block."

i didnt post that part of the question in the last post. i dont know if that helps, but i dont know the awnser to your question. i was given this question to solve.

4. why, then, did you mention the Pythagorean theorem?

5. Originally Posted by 14041471
i think it involves the pythagorem theorem but not really sure how to apply it. any help would be much appreciated.

"Mass of wood block without any weight = 5.0 kg; g = 9.8 m/s2"

"It was observed that the spring scale reached a force of 24.0 N to get the block moving from rest. Calculate the coefficient of static friction between the wood block and the table."
i believe were talking about applied force

use the frictional force equation;

mu*m*g=mu*5.0*9.8=49mu=24=24/49=0.489

plot the values and you will see

The block is sliding (I assume at constant velocity) therefore $\displaystyle F_{net} = \mu R$ where $\displaystyle R$ is the normal reaction force.
Getting the value of $\displaystyle R$ is simple and you're given the value of $\displaystyle F_{net}$ (the reading of the spring scale). Substitute the values and solve for $\displaystyle \mu$.