Question

The drawing shows three identical springs hanging from the ceiling. Nothing is attached to the first spring, whereas a W = 5.05-N block hangs from the second spring. A block of unknown weight hangs from the third spring. From the drawing, determine the spring constant (in N/m) and the weight of the block hanging from the third spring. (a) the spring constant N/m (b) the weight of the block hanging from the third spring N

Answer 1

a)

Distance between end point of first spring and and end point of second spring is $x=35\,cm-20\,cm=15\,cm=0.15\,m$

weight from second spring is $W=5.05\,N$

force of spring is $F=kx$

$kx=5.05$

$k(0.15)=5.05$

spring constant is $k=33.7\,N/m$

b)

Distance between end point of first spring and and end point of third spring is $x=50\,cm-20\,cm=30\,cm=0.30\,m$

weight from third spring is $W_1$

$W_1=kx$

$W_1=33.7\times0.30=10.1\,N$