Chapter 11- Rotational Equilibrium
Terms in this set (33)
produced by a torque
distance from a turning axis to the point of contact
Define lever arm.
produces rotational acceleration
What is true of torque?
-caused by a turning force
-caused by an applied force acting through a lever arm
If you apply a _____ to an object, it will likely rotate.
T/F? The longer the handle of a claw hammer, the greater the leverage when the hammer is used to pull a nail from a piece of wood.
What would produce the greatest torque?
large force, long lever arm
Two children with different weights sit on opposite sides of a seesaw. What must be true if the seesaw does not rotate?
The torque that tends to produce a clockwise rotation equals the torque that tends to produce a counterclockwise rotation
Explain how the sliding weights on a balance are used to bring the arm back to the horizontal position after a load has been placed on the pan.
The load produces a torque in one direction. The arm returns the horizontal position, by sliding the weights so that an equal and opposite torque is applied
T/F? When thrown end-over-end throughout the air, no part of a baseball bat follows a parabolic path.
What is true if an object that spins when it is thrown into the air?
- The object spins about its center of mass
- The object moves as if all its mass were concentrated at its center of mass
If a force applied to an object does not pass through the object's center of mass, the object will _________.
spin or rotate
T/F? For most objects on and near Earth, the center of mass and center of gravity vary greatly.
What is true about the center of gravity of an object?
- It is the average position of all of the particles of weight in an object
- It is often interchangeable with center of mass
- It is affected by the force of gravity
- For very large objects, it can be in a different location than the center of mass of that object.
If you throw a banana so that it rotated as it moves through the air, it will wobble about its ___________.
center of gravity
Explain why the center of gravity of the solar system is not at the sun's geometric center.
The masses of the planets contribute to the overall mass of the solar system. As the planets orbit the sun, their masses cause the sun to wobble off-center.
An object such as a meter sick can be supported by applying a force at its ________.
center of gravity
What describes the location of the center of gravity of an object that is suspended from a single point?
directly in line and blow (or at) the point of suspension
Describe how to find the center of gravity of an irregularly shaped object by suspending it.
Suspended the object from a single point and construct a vertical line beneath the point of suspension. Repeat using a different suspension point. the point where the lines intersect is the object's center of gravity.
T/F? The center of gravity of an object is always located a a point where the object physically exists.
Imagine a ring in the shape of a thin band. describe the location of the ring's center of gravity.
The center is located at the geometric center of the ring, at a location where no part of the ring exists.
T/F? If a vertical line extending down from an object's center of gravity extends outside its area of support, the object will topple.
T/F? Toppling occurs when an unbalanced torque exists.
T/F? Toppling occurs whenever the center of gravity is above the area of support.
T/F? The four legs of a chair define a rectangular support area on the floor beneath the chair.
T/F? Objects with large support areas are easier to balance.
T/F? Every person has a fixed center of gravity located somewhere in the lower body.
If a person stands with his or her arms at the sides of the body, where is the person's CG located?
within the person's body
The location of the CG in a women is slightly _____ than it is in a man.
T/F? A high jumper's CG can pass below the par as the jumper's body passes over the bar.
T/F? It is impossible to topple an object that is in stable equilibrium.
T/F? The height of an object's CG does not affect how stable it is.
The CG of an object tends to take the ____ position available.