Moderate -0.5 This is a straightforward application of standard SHM formulas. Finding maximum speed requires v_max = ωa (where ω = 2π/T and amplitude a is given), then the second part uses v = ω√(a² - x²). Both are direct substitutions into memorized formulas with no conceptual difficulty or problem-solving required, making it slightly easier than average.
2 The tip of a sewing-machine needle oscillates vertically in simple harmonic motion through a distance of 2.10 cm . It takes 2.25 s to perform 100 complete oscillations. Find, in \(\mathrm { m } \mathrm { s } ^ { - 1 }\), the maximum speed of the tip of the needle.
Show that the speed of the tip when it is at a distance of 0.5 cm from a position of instantaneous rest is \(2.50 \mathrm {~m} \mathrm {~s} ^ { - 1 }\), correct to 3 significant figures.
2 The tip of a sewing-machine needle oscillates vertically in simple harmonic motion through a distance of 2.10 cm . It takes 2.25 s to perform 100 complete oscillations. Find, in $\mathrm { m } \mathrm { s } ^ { - 1 }$, the maximum speed of the tip of the needle.
Show that the speed of the tip when it is at a distance of 0.5 cm from a position of instantaneous rest is $2.50 \mathrm {~m} \mathrm {~s} ^ { - 1 }$, correct to 3 significant figures.
\hfill \mbox{\textit{CAIE FP2 2009 Q2 [7]}}