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3 years ago

10 points

Physics

1 answer:

e-lub [12.9K]3 years ago

4 0

Answer:

e = 0.46 m

Explanation:

From the laws of friction, frictional force, F is proportional to normal reaction, R.

F₁ = μR

where μ is coefficient of friction; R = mg and g = 9.8 ms⁻²

Also, from Hooke's law, extension, e, in an elastic spring is proportional to applied force.

F₂ = Ke

where K is force constant of the spring

Since the box is just about to move, the coefficient of friction involved is static friction.

The force on the spring equals the frictional force experienced by the box the box; F₁ = F₂

Ke = μR

e = μR/K

where μ = 0.65; R = 18 kg * 9.8 ms⁻²; K = 250 N/m

e = (0.65 * 18 * 9.8)/250

e = 0.46 m

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