IB Physics question bank

Gravity still acts at the highest point, so the acceleration is $g$ downwards throughout the flight. Only the velocity is momentarily zero.

The current is $I=\frac{12}{4.0+6.0}=1.2\mathrm{A}$, so $V_2=1.2\times 6.0=7.2\mathrm{V}$.

In a transverse wave each part of the medium oscillates perpendicular to the direction in which the wave travels, about its own equilibrium position. The wave transfers energy along the rope, but there is no net displacement of the rope itself. A and D confuse the motion of the wave with the motion of the medium; C describes a longitudinal wave.

The induced emf is proportional to the rate of change of magnetic flux linkage. A1

Or as an equation: A1

$\mathrm{\Delta }\mathrm{\Phi }=0.40\times (0.050{)}^2=1.0\times {10}^{-3}\mathrm{W}\mathrm{b}$ M1

$\epsilon =\frac{200\times 1.0\times {10}^{-3}}{0.25}$ M1

$=0.80\mathrm{V}$ A1

The maximum kinetic energy depends only on frequency: $E_{k,\max }=hf-\mathrm{\Phi }$. Doubling the intensity doubles the number of photons per second, so twice as many electrons are emitted and the current doubles.