23-24 3rd Six Weeks Review

Engineers are considering using magnesium as a potential replacement for the lithium inside of rechargeable batteries. Magnesium would be a safer, more energy-dense option than lithium. What type of energy are these engineers investigating?

• Kinetic energy due to the movement of protons in the battery

• Thermal energy due to the heat dissipated in the battery

• Solar energy due to the movement of photons in the battery

• Potential energy due to the chemical reaction in the battery

Which of the following situations is an example of kinetic energy being transformed into potential energy?

• Throwing a ball high into the air

• Dropping a ball from a ladder

• Rolling a ball on the ground

• Holding a ball in the air without moving it

Which of the following is the best example of kinetic energy being transformed into potential energy?

• A ball rolling up a hill

• Bending a paper clip

• Coasting down a hill on a bicycle

• Starting an automobile engine

Which of the following does not contribute to the potential energy of an object?

• Height of the object above the Earth's surface

• Gravitational constant, or g, of the Earth

• Velocity of the object

• Mass of the object

A student releases a ball from a height of 1.5 m above the floor. Which of the following statements best describes the energy of the ball as it falls?

• Its potential energy is changed to kinetic energy.

• The total amount of its mechanical energy increases.

• Its kinetic energy is changed to potential energy.

• The total amount of its mechanical energy decreases.

A 12 N net force is applied to an object as it moves a distance of 3.0 m. Use the Work-Kinetic Energy Theorem to determine the object's change in kinetic energy. Enter your answer in Joules.

• 4 J

• 36 J

• 15 J

• 9 J

A tennis ball launcher works by using a spring to propel the ball forward as shown below: One model of tennis ball launcher has advertised that it is capable of imparting 15,000 J of kinetic energy to a 0.5 kg ball initially at rest. A student carefully measures the compression of the spring to be 0.10 m. What is the value of the spring constant for the tennis ball launcher according to the data provided?

• 1,732 N/m

• 3,000,000 N/m

• 6,000,000 N/m

• 3.6 X 1013 N/m

A geothermal system works to supply heat from deep underground in order to heat or cool a structure. These systems take advantage of the relatively constant temperature underground. Students were asked to predict the heat flow in the summer and winter. Their predictions were recorded below. According to the information given above, which student's prediction best describes the movement of heat in both the summer and winter?

• Andrea

• Betty

• Carlos

• Darius

A student is investigating the relationship between pressure, temperature, and entropy. A student manages to obtain a sample of ice, water, and water vapor that all coexist at the same temperature called the triple point. Which will have the greatest entropy at the triple point?

• Solid

• Liquid

• Gas

• The entropy will be equal in all states.

A student is at home on a hot summer day when the air conditioning stops working. The student opens the door to the refrigerator and seals off the kitchen from the rest of the house. Which best describes the change in temperature and entropy of the air molecules in the kitchen?

• Temperature and entropy decrease

• Temperature decreases and entropy increases

• Temperature increases and entropy decreases

• Temperature and entropy increase