A spring has natural length 40 cm and spring constant 500 N m⁻¹. A block of mass 1 kg is attached at one end of the spring and other end of the spring is attached to ceiling. The block released from the position, where the spring has length 45 cm.
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Question

A spring has natural length 40 cm and spring constant 500 N m⁻¹. A block of mass 1 kg is attached at one end of the spring and other end of the spring is attached to ceiling. The block released from the position, where the spring has length 45 cm.

Select all that apply

G1 Physics · Accepted Answer

Equilibrium extension is mg/k=(1×10)/500=0.02 m=2 cm, so equilibrium spring length is 42 cm. Released from 45 cm, the amplitude about equilibrium is 3 cm, so A is false. Angular frequency is √(500)=10√5 rad s⁻¹; therefore vₘₐₓ=ωA=30√5 cm s⁻¹ and aₘₐₓ=ω²A=15 m s⁻², so B and C are true. During the oscillation the spring length ranges from 39 cm to 45 cm and passes through its natural length 40 cm, where spring potential energy is zero; hence D is also true. Correct answers: B, C and D.