A ball attached to the end of a string is whirled on a horizontal circle at constant speed.
Consider the linear momentum, total energy, and kinetic energy of the ball throughout its motion.
Which of the following statements is true?
Both linear momentum and kinetic energy are not constant
Both total energy and linear momentum are constant
Linear momentum is constant but energy is not constant
Linear momentum is not constant but total energy is constant
Both total energy and linear momentum are not constant
i would choose the second option..both total energy and linear momentum are constant. Is this correct?
tot. energy because kinetic energy is same since speed is the same and potential energy same since height stays the same.
I'm not sure about linear momentum.. could someone explain?
well linear momentum means straight line and im not sure, considering it is travelling in a circle.
ur form utsc right? cuz i'm doing this also lol
To determine which statement is true, we need to understand the concepts of linear momentum, total energy, and kinetic energy.
Linear momentum is defined as the product of an object's mass and its velocity. It is a vector quantity, meaning it has both magnitude and direction. In the context of the ball whirled on a horizontal circle, the magnitude of the linear momentum remains constant since the speed of the ball is constant. However, the direction of the linear momentum changes continuously.
Total energy of an object is the sum of its kinetic energy and potential energy. Kinetic energy is the energy possessed by an object due to its motion and is proportional to the square of its velocity. Potential energy, in this case, is negligible since the ball is moving in a horizontal circle. Therefore, the total energy is essentially the kinetic energy.
Given that the ball is whirled at a constant speed, the magnitude of the velocity and thus the kinetic energy remains constant. However, since the direction of the velocity changes continuously as the ball moves in a circle, the kinetic energy is not constant.
Therefore, the correct statement is:
Linear momentum is constant, but energy (kinetic energy) is not constant.