A car moves in a straight line with a constant horizontal acceleration
PHYSICS · Multi-part · A Level · Physics · Mechanics and materials · Mechanics and materials
Problem
A car moves in a straight line with a constant horizontal acceleration a. A small pendulum of length l is suspended from the roof of the car. The bob remains at rest relative to the car, making a steady angle θ with the vertical.
(a) Draw all the forces acting on the bob as observed by a passenger sitting inside the car.
(b) By resolving the forces into convenient components and applying the condition for equilibrium, derive an expression relating tanθ to a and g.
(c) If a=3ms−2 and g=9.8ms−2, calculate the value of θ (in degrees, correct to two significant figures).