Question

• Describe torque, rotational equilibrium and angular acceleration.
• In your own words, explain rotational work and power.
• In your own words, explain conservation of angular momentum. PLEASE PRINT NO CURSIVE THANK YOU!

Answer 1

One could define Force as "that which cause objects to accelerate"
In the same way, Torque can be defined as ' that which can cause objects to accelerate angularly" or " that which can change the object's angular velocity"

Rotational equilibrium
like in translation equilibrium sum of all the forces is zero similarly in rotational equilibrium sum of all the torques is zero means zero net torque is zero

Angular acceleration
It is the rate of change of angular velocity with a time of an object in motion. Acceleration is the change in velocity of moving an object with respect to time. If the object moves on a circular direction than its velocity is called angular velocity.

Rotational work and Power
Work is a force applied over a distance and involves the transfer of energy from one type to another. Whenever energy is transferred between types, work is being done somewhere. But for you to do work on an object - for example, for you to do work on the books - you have to apply a force to them and cause them to move in the direction of that force. So if you had lifted the books, you would most certainly have been doing work. But since you were just holding them in place, you did no work at all. You applied a force, but your distance was zero.
The translational equation for work is force multiplied by distance. A greater force means greater work, but we're talking about rotation. Instead of force, in rotation, we have torque. And instead of moving a distance, in rotation, we rotate around an angle. So the rotational equation for work says that work, measured in joules, is equal to torque (tau), measured in newton-meters, multiplied by the change in angle (theta), measured in radians, not degrees.
Power is the work done per second in other words energy used per second measured in Watts. so if work is torque multiplied by the change in angle the power is obtained.

Conservation of Angular Momentum
Conservation of angular momentum is a physical property of a spinning system such that its spin remains constant unless it is acted upon by an external torque; put another way, the speed of rotation is constant as long as net torque is zero.

Angular momentum, also known as spin, is the velocity of rotation of something around an axis. Gyroscopes are simple devices that exploit the conservation of angular momentum to stabilize, guide or measure rotational movement in many types of systems. The law of conservation of angular momentum explains why a toy gyroscope or a spinning top remains upright as it turns rather than submitting to the force of gravity and toppling over.

Wheels on a bicycle act like gyroscopes as they spin up to speed, making it easier for the bicycle to stay upright and making it harder for anything to upset its momentum. The ability of a figure skater to increase his spin by pulling his arms closer to his body is another example of the conservation of angular momentum at work, as is the increase of an orbiting planet's spin as it gets closer to the sun.