A block of mass 3.7 kg is resting on a horizontal surface with a static coefficient of friction, µ=1.3. A spring with a constant 470 N/m is attached to the block and someone pulls on the other end of the spring. By how much does the spring extend before the block begins to move? g=9.81m/s2.
2007-11-30 12:10:30 · 2 answers · asked by A Saucerful of Secrets 2 in Science & Mathematics ➔ Physics
oh my goodness nyphdinmd, you are my hero. thank you SO much!
2007-11-30 12:22:14 · update #1
so are you teddy boy. you're my hero too.
2007-11-30 13:16:25 · update #2
The maximum static friction, Fmax = μsFn = 1.3(3.7)(9.8)
Fmax = 47.1 N.
From Hooke's Law: F = ks, where F is the applied tension force, k is the constant, and s is the elongation.
For this problem, for the block to start moving, F = Fmax.
Hence,
ks = 47.1
s = 47.1/470
s = .1 m or 10 cm ANS
teddy boy
2007-11-30 12:34:37 · answer #1 · answered by teddy boy 6 · 0⤊ 0⤋
The block with move when the force exerted by the spring equals the force of static friction:
kx = u*N = u*mg Solve for x
x = umg/k = 1.3*3.7*9.8/470 = 0.100 m
2007-11-30 20:20:09 · answer #2 · answered by nyphdinmd 7 · 0⤊ 0⤋