The angular frequency of a spring–block system is ω₀. It is suspended from the ceiling of an elevator moving downward at constant speed v₀. The block is at rest relative to the elevator. The lift is suddenly stopped. Taking downward as positive, choose the wrong statement.
Options

Question

The angular frequency of a spring–block system is ω₀. It is suspended from the ceiling of an elevator moving downward at constant speed v₀. The block is at rest relative to the elevator. The lift is suddenly stopped. Taking downward as positive, choose the wrong statement.

Options

G1 Physics · Accepted Answer

When the elevator suddenly stops, the block is at the old equilibrium with downward velocity v₀. The new motion about the same equilibrium starts from x=0 with v=v₀, so x=(v₀/ω₀)sinω₀t. Thus amplitude=v₀/ω₀ and maximum speed=v₀. Initial phase is 0, not π. Therefore statement 2 is wrong. Correct option: 2.