SONAR

^{WHAT DOES SONAR NOT MEASURE ?}

• DISTANCE
• PRESSURE
• DIRECTION
• SPEED

When a sound hits a surface it is

•  reflected
• echoed
• lost

 Bats detect the obstacles in their path by receiving the reflected

• infrasonic waves
• radio waves
• electro-magnetic waves
• ultrasonic waves

Bats catch their prey using the process of

• Echolation
• Echo-Ranging
• Ultrasound
• Reflection

What measures the time difference between the sound and its echo?

• hearing aid
• sonar device
• solar plant

Why doesn't sonar work well in the air?

• air is less dense than water
• air is more dense than water
• air does not carry sound waves as fast as water
• A and C

There is a ship that sends a pulse of ultrasound and after 0.3 seconds receives an echo . Consider the sound speed in water  as  1500 m/s  .Then calculate the  depth of sea .

• 227
• 226
• 227
• 225

A Ship transmits an ultrasonic sound. The wave reflects from the seabed and is detected by the detector of the ship. The distance between the transmitter of the ship and the seabed is 4000 m. The speed of ultrasonic sound in seawater is 1531 m/s.What is the time gap between transmission and detection?

• 1.82sec
• 2.56sec
• 4.14sec
• 5.23sec