A crop-spraying drone flies horizontally in a straight line while continuously dispersing liquid fertilizer. The drone's engines provide a constant forward thrust force, and air resistance is negligible.
The time taken for the drone to accelerate from rest to its cruise speed decreases as the drone's tank empties.
This time decreases because:
the drag force on the drone decreases.
the chemical spray creates an additional forward reaction force.
the acceleration of the drone increases.
the maximum speed of the drone decreases.
84 exam-style questions on AQA A Level Physics Force, energy and momentum, covering Scalars and vectors, Moments, Motion along a straight line, Projectile motion, Newton's laws of motion, Momentum, Work, energy and power, and Conservation of energy. Each one has a worked solution and a mark scheme showing where the marks go.