A small object of mass M and charge Q is connected to an insulating massless string in vacuum on Earth. A uniform electric field exists throughout the region of the vacuum as indicated. The mass remains in static equilibrium at an angle of θ with the vertical as shown in the figure. When the string is cut, which of the illustrated paths best indicates the trajectory of the mass?

Question

G1 Physics · Accepted Answer

Step 1: In a uniform electric field the charge has constant acceleration 𝐚 = q𝐄/m, so the motion is mathematically identical to projectile motion. Step 2: Resolve the initial velocity and use x = uₓt, y = uᵧt + (1/2)at². Step 3: Impose the target/trajectory condition and solve for angle or time. Final: Option B.