A student hangs a spring vertically from a hook, as shown in Figure below. F3 End Term 1 Physics Q13b With no load, the spring is 12.0 cm long. With a load of 2.0 N on the end of the spring, its length is 15.0 cm. Calculate the extension of the spring.

Question

1. A student hangs a spring vertically from a hook, as shown in Figure below.
   
   With no load, the spring is 12.0 cm long. With a load of 2.0 N on the end of the spring, its length is 15.0 cm. Calculate the extension of the spring.
2. When the graph of extension against load is drawn for the spring, the result is the line shown below.
   
   The unstretched length of the spring is 9.0 cm.
   1. Calculate the total length of the spring when a 5.0 N load is hanging from the spring. 
   2. Calculate the energy stored in the spring when it stretches through 2cm
   3. Calculate the spring constant from the graph

Answer 1

1.  15.0cm -12.0cm = 3.0cm
2.  
   1. F= Ke
      5 = K ×   2 
                  100 
      2k=500
      k=250N/m
   2. P_E = ½Ke²
          =½ × 250 × 0.01 × 0.02
          =0.05J
   3. ^F/_e = K
      (5, 2), (3, 1.2)
      ∆ = ∆y = 2 − 1.2 = 0.8
            ∆x      5−3         2
         ^e/_F = 0.4
      ^F/_e = ¹/_0.4 = ¹⁰/₄ × 100
          =250N/m