a force of 2N stretches an elastic material by 30mm. What additional force will stretch the material by 35mm assuming the elastic limit is not exceeded
From hooks law
F=ke
2=k x 30/1000
K= 2000/30
The force stretching the material 35mm be F
F=k x 35/1000 = 2000/30 * 35/1000
7/3 = 2.33
Additional force = -2 + 2.33
= 0.33N
30mm = 0.030m.
k = 2N./0.03m = 66.7 N/m.
F = 66.7N/m * 0.035m - 2N. = 2.33 - 2 = 0.33 N. = Addition force.
correct OK thank
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