Work and Energy Scenarios Level 1.5 24.25

A mass m is moving at an initial constant velocity v on a surface with negligible friction.  The mass then encounters a rough section of length d with a kinetic coefficient of friction μ_k.

    The block system is __________ when the block is moving on the smooth surface.

• problem

• isolated

• closed

• open

A mass m is moving at an initial constant velocity v on a surface with negligible friction.  The mass then encounters a rough section of length d with a kinetic coefficient of friction μ_k.

What is the change in kinetic energy of the box before it encounters the rough section?

• 0.5 m v squared

• positive change

• negative change

• zero change

A mass m is moving at an initial constant velocity v on a surface with negligible friction.  The mass then encounters a rough section of length d with a kinetic coefficient of friction μ_k.

    The work done BY the smooth surface is equal to _________.

• a mathematically related headache

• zero

What is the change in kinetic energy for a system defined as closed?

• The change in kinetic energy is equal to the work done on the system.
• Kinetic energy is independent of work done on the system.
• The change in kinetic energy is zero.

• The change in kinetic energy is equal to the potential energy of the system.

A mass m is moving at an initial constant velocity v on a surface with negligible friction.  The mass then encounters a rough section of length d with a kinetic coefficient of friction μ_k.

    The block system is __________ when the block is moving on the rough section of the surface.

• problem

• isolated

• closed

• open

A mass m is moving at an initial constant velocity v on a surface with negligible friction.  The mass then encounters a rough section of length d with a kinetic coefficient of friction μ_k.

What is the change in kinetic energy of the box as it encounters the rough section?

• 0.5 m v squared

• positive change

• negative change

• zero change

A mass m is moving at an initial constant velocity v on a surface with negligible friction.  The mass then encounters a rough section of length d with a kinetic coefficient of friction μ_k.

    The work done BY the rough surface is equal to _________. (select 2 options)

• zero

• A mathematically related headache

A mass m is moving at an initial constant velocity v on a surface with negligible friction.  The mass then encounters a rough section of length d with a kinetic coefficient of friction μ_k. After the block leaves the rough section, the amount of energy the block has is equal to the initial kinetic energy combined with the work done by friction. Which of the following equations is correct for the above statement?

A mass m is moving at an initial constant velocity v on a surface with negligible friction.  The mass then encounters a rough section of length d with a kinetic coefficient of friction μ_k. After the block leaves the rough section, the amount of energy the block has is equal to the initial kinetic energy combined with the work done by friction. Which of the following equations is needed to solve for the final velocity of the block AFTER it encounters the rough section?

A block of mass m is placed above an uncompressed vertical spring with a spring constant of k mounted to a table.  The block is lowered gently on the spring and causes the spring to compress from its original length of x₁ to a compressed length of x₂. 

In this scenario we would consider the spring-block-Earth system as ________.

• open

• closed

• isolated

• complicated