Physics: Chapter 11 Study Guide
. Circle the letter of each statement that is true. a. Toppling occurs when an unbalanced torque exists. b. Toppling occurs when a vertical line through the CG falls within the object's base. c. Toppling occurs whenever the CG is above the area of support. d. Toppling is more likely to occur in objects with small support areas
A+C
. Circle the letter of each statement that is true about the center of gravity of an object. a. It is the average position of all of the particles of weight in an object. b. It is often interchangeable with center of mass. c. It is affected by the force of gravity. d. For very large objects, it can be in a different location than the center of mass of that object.
ABCD
Circle the letter that describes the location of the CG of an object that is suspended from a single point. a. at the point of suspension b. directly in line and below (or at) the point of suspension c. outside the object d. directly in line and above (or at) the point of suspension
B
Circle the letter that shows when the cone is in stable equilibrium. a. Part a only b. Part b only c. Part c only d. Parts b and c
B
Circle the letter of each statement that is true of an object that spins when it is thrown through the air. a. All parts of the object follow a parabolic path. b. The object spins about its center of mass. c. The object moves as if all its mass were concentrated at its center of mass. d. No part of the object follows a parabolic path.
B+C
Circle the letter of each statement that is true of torque. a. tends to produce linear acceleration b. caused by a turning force c. caused by an applied force acting through a lever arm d. is the same as force
B+C
. Circle the letter of each statement that is true. a. Objects with a CG high above their support are easy to balance. b. No object can ever truly be in balance. c. Objects with large support areas are easier to balance. d. Only a computer can balance an object like an electric scooter.
C
An object such as a meter stick can be supported by applying a force at its____-
Center of Gravity
If you throw a banana so that it rotates as it moves through the air, it will wobble about its_______
Center of Gravity
Circle the letter of the description that would produce the greatest torque. a. small force, short lever arm b. small force, long lever arm c. large force, small lever arm d. large force, long lever arm
D
Two children with different weights sit on opposite sides of a seesaw. Circle the letter of the statement that must be true if the seesaw does not rotate. a. The children are sitting at equal distances from the pivot point. b. The seesaw must be broken because it is not moving. c. The lighter child is sitting closer to the pivot point. d. The torque that tends to produce a clockwise rotation equals the torque that tends to produce a counterclockwise rotation.
D
. Is the following sentence true or false? For most objects on and near Earth, the center of mass and center of gravity vary greatly
False
. Is the following sentence true or false? The center of gravity of an object is always located at a point where the object physically exists
False
8. Is the following sentence true or false? Every person has a fixed center of gravity located somewhere in the lower body.
False
Is the following sentence true or false? It is impossible to topple an object that is in stable equilibrium
False
Is the following sentence true or false? The height of an object's CG does not affect how stable it is.
False
Is the following sentence true or false? When thrown end-over-end through the air, no part of a baseball bat follows a parabolic path.
False
Use the definition of torque (torque = force> lever arm) to explain why the applied torque increases in the illustrations A - C above.
In the illustration B, the perpendicular component of the force is greater than it is in illustration A. In illustration C, the longer lever arm increases the applied torque.
The CG of an object tends to take the________ position available.
Lowest
Explain why standing with your feet farther apart than normal makes it easier to stand during a bumpy bus ride.
Placing your feet farther apart increases your base area of support.
f a force applied to an object does not pass through the object's center of mass, the object wil_______
Spin or Rotate
Describe how to find the center of gravity of an irregularly shaped object by suspending it.
Suspend 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
Is the following sentence true or false? If a vertical line extending down from an object's CG extends outside its area of support, the object will topple.
T
Is the following sentence true or false? The CG of the cone shown in Part c does not change no matter which direction the cone rolls.
T
Is the following sentence true or false? The four legs of a chair define a rectangular support area on the floor beneath the chair.
T
Placing your feet farther apart increases your base area of support.
The CG of the cone is lowered.
Imagine a ring in the shape of a thin band. Describe the location of the ring's center of gravity
The center of gravity is located at the geometric center of the ring, at a location where no part of the ring exists.
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. By sliding the weights so that an equal and opposite torque is applied, the arm returns to the horizontal position.
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
If you apply a________ to an object, it will likely rotate.
Torque
Is the following sentence true or false? A high jumper's CG can pass below the bar as the jumper's body passes over the bar.
True
Is the following sentence true or false? 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.
True
If a person stands with his or her arms at the sides of the body, where is the person's CG located?
Within the persons body
lever arm
distance from a turning axis to the point of contact
The location of the CG in a woman is slightly [short wol] than it is in a man
lower
rotation
produced by a torque
torque
produces rotational acceleration
