A car is accelerating horizontally at a rate of 2.5 m/s². A mass of 250 g is hanging from the ceiling on a string 1.2 m long. The angle that the string makes with the vertical is A) 14.3^o toward the back of the car. B) 76^o toward the back of the car. C) 7^o toward the front of the car. D) 14.3^o toward the front of the car. E) 0^o, or straight down.

Question

Quizplus · Accepted Answer

The correct answer is A because the car is accelerating horizontally, so the mass will swing toward the back of the car. The angle that the string makes with the vertical is given by:$$	heta = 	an^{-1}(\frac{a}{g}) = 	an^{-1}(\frac{2.5 \ m/s^2}{9.8 \ m/s^2}) = 14.3^o$$

A Car Is Accelerating Horizontally at a Rate of 2