Energy Basics
Energy is the ability to…
change or move matter.
Kinetic energy depends on these two properties?
mass & speed
Name an example of elastic potential energy.
a stretched slingshot
A disturbance that carries energy is called a...
wave
The height of a wave from rest to crest is the…
Amplitude
What is the correct unit for energy?
Joule
Calculate gravitational potential energy for:
a 4 kg box at 2 m height
Formula: GPE = mass x height
GPE = 4 kg x 2 m = 8 Joules
Which energy travels as waves and does NOT need a medium?
Electromagnetic Energy
In a transverse wave, particles move…
Transverse particles move perpendicular to energy.
The distance between matching points on a wave is the…
wavelength
Which statement is TRUE?
A. Energy is created when objects move
B. Energy is neither created nor destroyed
C. Energy disappears when not used
D. Ears convert sound into matter
B
Give an example of energy transforming from one type to another (not a roller coaster, diver, or slingshot)
Answers vary: Walking around the hallway converts chemical energy (from food we eat) into kinetic energy (moving in the halls).
Which type of energy is stored in bonds of molecules?
Chemical
There are two main types of waves (based on whether they need a medium to travel). List them.
Mechanical waves & Electromagnetic waves.
As frequency increases, wavelength…
gets shorter.
When energy is transferred (passed) from one object to another, we call this…
Work
A 10 kg dog runs at 3 m/s.
What is its KE?
KE = ½×m x v2
KE = ½×10 × 32
KE = 5 x 9 = 45 Joules
Which form of energy is produced by vibrating matter?
Sound
Compression and rarefaction occur in…
longitudinal waves (like sound).
Increasing amplitude _____ energy.
increases