A. A heat engine has an efficiency of 0.3. If the engine takes in 10000 J of heat per cycle, how much heat is discarded per cycle? B. A clay is put at the edge of a potter’s wheel of radius 0.800 m. The wheel is at rest at t = 0 and it starts rotating with a constant angular acceleration. If its angular speed at t = 3.50 s is 2.80 rad/s, what is the tangential acceleration magnitude of the clay? C. A merry-go-round of radius 2.00 m is slowing down at a constant angular acceleration of −5.00 rad/s^2. A butterfly sits at the edge of the merry-go-round when the angular velocity is +14.0 rad/s. What is the total distance traveled by the butterfly until it stops? D. An amount of heat 120 J is taken from a hot reservoir at a temperature of 393 K and discarded to a cold reservoir at a temperature of 293 K. What is the entropy
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.
A. A
B. A clay is put at the edge of a potter’s wheel of radius 0.800 m. The wheel is at rest at t = 0 and it starts rotating with a constant
C. A merry-go-round of radius 2.00 m is slowing down at a constant angular acceleration of −5.00 rad/s^2. A butterfly sits at the edge of the merry-go-round when the
D. An amount of heat 120 J is taken from a hot reservoir at a temperature of 393 K and discarded to a cold reservoir at a temperature of 293 K. What is the entropy change of the universe?
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