Non-conservative Force and the work-energy Theorem

A pendulum swings in a vertical plane. At the bottom of the swing, the

kinetic energy is 8 J and the gravitational potential energy is 4 J. At the highest

position of the swing, the kinetic and gravitational potential energies are :

• kinetic energy =0 J and gravitational potential energy =4 J.

• kinetic energy = 12 J and gravitational potential energy= 0 J

• kinetic energy = 0 J and gravitational potential energy= 12 J

• kinetic energy = 4 J and gravitational potential energy= 8 J

Which of the following is not a unit of energy?

• newton-meter

• joule

• Kilowatt-hour

• all of the above

A baseball is dropped from the top of a building. Air resistance acts on the baseball as it drops. Which of the following statements is true?

• $E_{tot_{ }}=\Delta K+\Delta U+E_{other}$

• $E_{tot}=\Delta K\ +\Delta U$

• $E_{tot}=0$

• at A=50J , C=50J

• A=100 , C=0J

• A=50J , C=0J

• A=0 , C=100J

the friction does not do work in the way that a conservative force dose. its converts Kinetic and /or potential energy into

• internal excitation energy

• vibration energy

• deformation energy

• All of the above