part (b)
weight of block = normal force = m g
= 3.5 * 9.81 = 34.3 Newtons
maximum static friction force = .52*34.3
= 17.85 N
That is the spring force you need
17.85 = k x
17.85 = 75 x
x = .238 meters = 23.8 cm
A block with a mass m = 3.50 kg sits on a surface with a coefficient of static
friction µs = 0.520. A spring with spring constant k = 75.0 N/m is hooked onto the
block, and is slowly pulled horizontally, gradually stretching the spring. (a) When
the spring is stretched 10.0 cm, the block is still stationary. What is the friction force
felt by the block when the spring is stretched 10.0 cm? (b) How much is the spring
stretched when the block just begins to move?
I've done the first part but i'm having trouble knowing what formula to use for the second one. I know you have to use the coefficient of static friction. So i used it to calculate the normal Reaction, but i'm still stuck.
Formulas i have:
F=uN, F=mg, F=ke
Thanks in advance
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