Unit 5 Conservation of Energy

Choose the following scenarios which are considered WORK. Remember: Work is only given to an object when the displacement (position) has changed. (More than one choice)

• Man holds out heavy concrete block at arm’s length for 10 minutes

• Student pushes car down street

• Women holds up a large box over-head while walking down the hall way

• Child pushes a cart along the side walk

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.

Tags

NGSS.HS-PS1-2

NGSS.HS-PS1-4

NGSS.HS-PS3-2

A tennis ball launcher works by using a spring to propel the ball forward as shown. One model of tennis ball launcher has advertised that it is capable of imparting 15, 000J of kinetic energy to a 0.5 kg ball initially at rest. A student carefully measures the compression of the spring to be 0.10m. Refer to the information and image above. What is the elastic energy stored in the spring?

• 0 J

• 7,500 J

• 15,000 J

• 30,000 J

Tags

NGSS.HS-PS3-3

Conveyor belts are often used to move packages around warehouses. The conveyor shown

below moves packages at a steady 4.0 m/s. A 500 N employee decides to catch a ride by

sitting on a 1,000 N box for a 50 m trip as shown. What is the work done by the employee on the box shown above?

• 0 J

• 500,000 J

• 1,000,000 J

• 1,500,000 J

A student examines the relationship between gravitational potential energy and position of a ball above the ground as shown in the graph shown. What does the slope of the above graph represent?

• Acceleration due to gravity

• Mass

• Potential energy

• Weight

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

Tags

NGSS.HS-PS3-3

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

Tags

NGSS.MS-PS3-2

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

Tags

NGSS.HS-PS3-3

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

Tags

NGSS.HS-PS1-2

NGSS.HS-PS3-2

Three runners, each 70 kg, leave the starting line at the bottom of a hill and race to the top of the hill. All runners take different paths as shown. Which runner had the greatest power during the race according to the data above?

• Runner A

• Runner B

• Runner C

• All runners are equally powerful.

Tags

NGSS.MS-PS3-1

NGSS.MS-PS3-5