When a particle starts from rests and moves with constant acceleration then why its path is always a straight line?
The path of a particle that starts from rest and moves with constant acceleration is not always a straight line. In fact, it is commonly known that a particle under constant acceleration follows a curved path. The curvature of the path is determined by the magnitude and direction of the acceleration.
One reason why people might think the path is always a straight line is due to a special case: when the particle's velocity is constant (i.e., zero acceleration) after some initial acceleration. In this case, the particle continues with the constant velocity, and its path will be a straight line.
To better understand why the path is not always straight, it is essential to look at the physics behind it. According to Newton's second law of motion, the net force acting on an object is equal to its mass multiplied by its acceleration (F = m * a). When the net force is non-zero, the particle will experience acceleration, leading to changes in its velocity and thus its path.
If the net force is constant and nonzero, the particle will experience constant acceleration throughout its motion. In this scenario, the path will be curved. The specific shape of the curve depends on the magnitude and direction of the acceleration and can be described mathematically using equations of motion.
In summary, the path of a particle moving with constant acceleration is generally curved, and it becomes a straight line only if the particle's final velocity after the initial acceleration remains constant.