To measure the static friction coefficient between a 2.0-kg block and a vertical wall, the setup shown in the drawing is used. A spring (spring constant = 475N/m) is attached to the block. Someone pushes on the end of the spring in a direction perpendicular to the wall until the block does not slip downward. If the spring in such a setup is compressed by 0.049m, what is the coefficient of static friction?
2007-01-04 05:22:24 · 2 answers · asked by Anonymous in Science & Mathematics ➔ Physics
the drawing has a wall on the left side with a block attached and a string attached to that with a hand pulling on it
2007-01-04 05:31:32 · update #1
First, do a force balance to show that the block stops slipping when the upwards force of friction equals the downwards force of gravity, so F_friction = mg. Next, calculate the force in the spring. This is done by multiplying the spring constant by the compression distance, F_spring = kx. That is the force being applied to the block, and it is equal to N, the normal force that the wall exerts on the block. Then calculate the force of friction on the block, using F_friction = uN, where u is the coefficient of static friction. So now we have F_friction = mg ==> uN = mg ==> ukx = mg, and u is your only unknown.
2007-01-04 05:26:10 · answer #1 · answered by DavidK93 7 · 2⤊ 0⤋
We can't answer this without seeing the setup shown in the drawing, really - only guess at what the setup would be.
Maybe you could use some of the equations in that physics book of yours to help you, eh?
2007-01-04 05:25:48 · answer #2 · answered by MamaMia © 7 · 0⤊ 0⤋