Analyze the explanation and identify any false statements. Each statement to be analyzed is identified by a capital letter. A ball is rotating in a horizontal plane on the end of a string of length l. (A) The rotational kinetic energy remains constant as long as the length and angular speed are fixed. (B) When the ball is pulled inward and the length of the string is shortened, the rotational kinetic energy will remain constant due to conservation of energy, (C) but the angular momentum L will not remain constant because there is an external force acting on the ball to pull it inward. (D) The moment of inertia I remains constant and (E) the angular speed will remain the same throughout the process because the ball is rotating in the same plane throughout the motion. Select all of the statements that are false.
Angular Momentum
The momentum of an object is given by multiplying its mass and velocity. Momentum is a property of any object that moves with mass. The only difference between angular momentum and linear momentum is that angular momentum deals with moving or spinning objects. A moving particle's linear momentum can be thought of as a measure of its linear motion. The force is proportional to the rate of change of linear momentum. Angular momentum is always directly proportional to mass. In rotational motion, the concept of angular momentum is often used. Since it is a conserved quantity—the total angular momentum of a closed system remains constant—it is a significant quantity in physics. To understand the concept of angular momentum first we need to understand a rigid body and its movement, a position vector that is used to specify the position of particles in space. A rigid body possesses motion it may be linear or rotational. Rotational motion plays important role in angular momentum.
Moment of a Force
The idea of moments is an important concept in physics. It arises from the fact that distance often plays an important part in the interaction of, or in determining the impact of forces on bodies. Moments are often described by their order [first, second, or higher order] based on the power to which the distance has to be raised to understand the phenomenon. Of particular note are the second-order moment of mass (Moment of Inertia) and moments of force.
Analyze the explanation and identify any false statements. Each statement to be analyzed is identified by a capital letter.
A ball is rotating in a horizontal plane on the end of a string of length l. (A) The rotational kinetic energy remains constant as long as the length and angular speed are fixed. (B) When the ball is pulled inward and the length of the string is shortened, the rotational kinetic energy will remain constant due to conservation of energy, (C) but the
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