This diagram shows how loud certain frequencies must be in
order for people of different ages to hear them. The needed
intensity is called the "hearing level."
According to the graph, what is the maximum age at which a
4000 Hz sound wave with an intensity of 20 dB would be
heard?
Hearing Level (dB)
500 Hz
1.000 Hz
2,000 Hz
3,000 Hz
4,000 Hz
-6,000 Hz
70
20
30
60
40 50
Age (Years)

Abicycle slows down when the rider applies the brakes. what type of energy transformation is involved in this example? a. kinetic energy into heat energy b. heat energy into potential energy c. potential energy into kinetic energy d. kinetic energy into mechanical energy

Simon is writing a story about an astronaut whose spacecraft has been boarded by space pirates. the astronaut has her lucky penny in her hand behind her back as the space pirates break into the control room. she has just locked the controls so that the ship is accelerating in the direction of the control room’s ceiling. simon wants the astronaut to use the penny to hit a button on the control panel to turn off the lights and escape. the button is located a short distance behind and below the astronaut’s hands. how should simon use the theory of relativity to describe what the astronaut must do in order to hit the button?

Smallest intensity of a stimulus that you can detect 50 percent of the time is