quiz #5 part 2
Which of the following forces is considered a conservative force?
Gravity
Which of the following forces is considered a conservative force?
The force due to a spring
What is true about the work done by a conservative force?
The work done by a conservative force is always path independent.
When helping a friend move into a new home, you push a chair across the room. What do you know about the force of gravity applied to the chair?
The force of gravity applied to the chair does not change the energy of the system (the chair) and therefore does no work on the system.
When helping a friend move into a new home, you push a chair across the room. What do you know about the force that you exert on the chair?
The force you exert on the chair contributes to the overall change in kinetic energy of the system (the chair) with a positive amount and therefore does positive work on the system.
When helping a friend move into a new home, you push a chair across the room. What do you know about the force of friction applied to the chair by the floor?
The frictional force applied to the chair contributes to the overall change in kinetic energy of the system (the chair) with a negative amount and therefore does negative work on the system.
A block slides along a rough surface and comes to a stop. What can you conclude about the frictional force exerted on the block?
The frictional force does negative work on the block and decreases its kinetic energy.
What is true about the work done by a non-conservative force?
The work done by a non-conservative force will always change the total mechanical energy of a system.
When you lift a book upward off of a table, what is true about the work done on the book by the force of gravity?
The work done by the force of gravity is negative and proportional to the upward displacement of the book.
You observe two identical balls of putty heading directly toward each other at equal speeds. What can you say about their total kinetic energy?
They have twice the kinetic energy of either ball by itself.
In which of these processes is the total energy of the system conserved?
Two balls of putty (the system) collide in midair and stick together.
A variety of forces are applied to an object such that the net force does positive work on that object. What can you conclude about the speed of the object?
When the total work done on the object is positive, the object's speed will increase.
The mechanical energy of a system is conserved during a certain process only if __________.
non-conservative forces do zero total work on the system during that process
If Quantity X is conserved for a certain system and during a certain process, that means__________.
quantity X for that system does not change in any way during that process
