Răspuns :
f1=100N.........
12cm=100N
3cm=xN
--------------------
12/3=100/X
x=(100×3):12
x=15
=>3cm =25 N
12cm=100N
3cm=xN
--------------------
12/3=100/X
x=(100×3):12
x=15
=>3cm =25 N
f1=100N.........
12cm=100N
3cm=xN
--------------------
12/3=100/X
x=(100×3):12
x=15
=>3cm =25 N