Science - ENERGY - Mechanical Energy

MECHANICAL ENERGY

TODAY’S TARGET: Recognize mechanical energy as the energy of motion.​

Multiple Choice

Students were planting seeds in a garden outside near the playground. The students used a shovel to help them move the dirt from one position to another so they could plant the seeds. What form of energy were the students using?

• heat

• chemical

• mechanical

• electrical

​MECHANICAL ENERGY

​Mechanical energy is the energy of motion. What is motion? Mr. Ted drove his Jeep from his house to a trail. He and his Jeep changed position from the house to the trail. Both objects moved. Movement is a change in position. While the objects are changing position, they are moving, or in motion. Because the Jeep’s engine caused that motion, the Jeep had mechanical energy. Then, when Mr. Ted got to the trail, he took his bike off the back of the Jeep, and rode the bike down the trail. The action of pedaling the bike caused its motion. The bike had mechanical energy because it was in motion and was powered by pedaling.

Multiple Choice

Which statement best defines Mechanical Energy?

• Energy produced by a machine or moving part.

• Energy that is produced by an electrical current in a circuit.

• Energy from the sun.

• Energy that travels in waves due to vibrations.

Multiple Choice

__________________ is a change in position

• Planting

• Heat

• Movement

• Light

​In examples of mechanical energy, we are going to look for easily recognizable sources of power for the motion that is happening. Ask, is there a machine or engine powering this motion? If there is, then it is an example mechanical energy. Is there a person doing an action that powers this motion? If there is, it is mechanical energy. For example, if the hands of the clock in your classroom are in motion, there is a battery powering a small motor, which moves the hand of the clock. Because there is a motor powering the hands, this is an example of mechanical energy.

Multiple Choice

What has to be true about an object for it to have mechanical energy?

• it must be moving

• it must be elevated

• it must be experiencing a net force

• it must be accelerating

Multiple Choice

What is energy?

• moving energy

• stored energy

• renewable energy

• The ability to do work.

Multiple Choice

Which is an example of mechanical energy?

• hearing your mom's voice on your cell phone

• watching a ball roll down a hill

• listening to a car horn get louder as it gets closer

• seeing a firecracker make sparks in the sky

Multiple Select

Gigi and Leah are learning about sound energy by stretching a rubber band. What types of things would they notice?

• pitch gets lower as the rubber band is stretched

• vibrations slow down when the band is stretched tighter

• pitch stays the same as the rubber band is stretched

• pitch gets higher as the rubber band is stretched

• vibrations are faster when the band is stretched tighter

​Cars, busses, trucks, planes, trains, and boats all use some form of mechanical energy when moving. Many of those things use engines to move. They are all examples of mechanical energy. If a boat has a motor, or someone is rowing or paddling the boat, then it has mechanical energy. Can you think of other examples of mechanical energy around you?

Multiple Choice

All of the following are examples demonstrating mechanical energy EXCEPT –

• an oven cooking food.
• a fan blowing out air. 
• a boy riding a bicycle.
• a girl writing with a pen.

Multiple Choice

Which of the following actions does not require mechanical energy to function?

• Sharpen a pencil.

• Riding a bike.

• Rotating a motor.

• Melting ice.

Multiple Choice

A student made a list of activities that involve energy.

1.Swimming in the river

2.Cooking a pizza in the oven

3.Watching TV

4.Climbing a tree

5.Playing soccer

Which activities on the list are examples of the use of mechanical energy?

• A. Activities 1, 3, 5

• B. Activities 1, 2, 4

• C. Activities 1, 4, 5

• D. Activities 2 and 3