An Ideal Spring, with a Pointer Attached to Its End

question 54

Multiple Choice

An ideal spring, with a pointer attached to its end, hangs next to a scale. With a 100-N weight attached, the pointer indicates "40" on the scale as shown. Using a 200-N weight instead results in "60" on the scale. Using an unknown weight X instead results in "30" on the scale. The weight of X is:

• A) 20 N
• B) 30 N
• C) 40 N
• D) 50 N
• E) 75 N