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smile97
Nov9-04, 10:24 PM
so i have tried this problem fifty million times and i can't get the right answer. hopefully someone can help. when a 75 g mass is suspended from a vertical spring, the spring is stretched from a length of 4.0 cm to a length of 7.0 cm. If the mass is then pulled downward an additional 10 cm, what is the total work done against the spring force in joules? i converted grams to kilograms and cm to m and used the equation f=kx and then plugged those numbers into w=1/2kx^2. i can't get the correct answer of 0.21 J. please help

Leong
Nov9-04, 10:53 PM
unfortunately, i get 0.1962 J; a wrong one .

Kurdt
Nov10-04, 05:58 AM
i get the correct answer of 0.21J

k=24.5
x=0.13

plug them in and out pops the answer