Echolocation - Revision history

NRJC at 13:46, 7 June 2019

2019-06-07T13:46:01Z

NRJC at 12:12, 4 April 2019

2019-04-04T12:12:27Z

NRJC: /* Example Calculations */

2019-04-03T19:54:22Z

‎Example Calculations

NRJC at 19:54, 3 April 2019

2019-04-03T19:54:09Z

NRJC: /* About Echolocation */

2019-04-03T19:53:27Z

‎About Echolocation

NRJC at 19:53, 3 April 2019

2019-04-03T19:53:13Z

NRJC at 18:40, 19 February 2019

2019-02-19T18:40:35Z

NRJC: /* Example Calculations */

2019-02-19T18:38:01Z

‎Example Calculations

NRJC: /* Example Calculations */

2019-02-19T18:37:43Z

‎Example Calculations

NRJC: Created page with "==Key Stage 4== ===Meaning=== Echolocation is a method for finding objects using reflected sound waves. ===About Echolocation=== Echolocation takes pl..."

2019-02-19T17:56:40Z

Created page with "==Key Stage 4== ===Meaning=== Echolocation is a method for finding objects using reflected sound waves. ===About Echolocation=== Echolocation takes pl..."

New page

==Key Stage 4==
===Meaning===
[[Echolocation]] is a method for finding [[object]]s using [[reflect]]ed [[sound]] [[wave]]s.

===About Echolocation===
[[Echolocation]] takes place in several steps:
#A [[sound]] is emitted.
#The [[sound]] travels until it hits an [[object]].
#The [[sound]] is [[reflect]]ed by the [[object]].
#The [[sound]] travels back to the emitter.
#The [[sound]] is detected.
: The time it takes the [[sound]] to return to its source can show how far away the [[object]] is located. Since the [[sound]] has to travel to the [[object]] and back again this time is twice as long as the time taken just to travel to the [[object]].

[[Echolocation]] is used by:
*[[Bat]]s - To avoid obstacles when flying and to find [[prey]].
*[[Dolphin]]s - To locate [[prey]] and the size and shape of their surroundings.
*[[Boat]]s - To find shoals of [[fish]] and to find the distance to the sea bed.
*[[Submarine]]s - To navigate underwater detecting the sea bed and to locate [[ship]]s.

===Equation===
''NB: You do not have to remember the equation in this form, but should be able to work it out for yourself and apply it.''

Distance = (Speed) x (Time)/2

The [[time]] is divided by two because the [[sound]] wave must travel to the [[object]] and then back again to the detector.

<math>x = v \frac{t}{2}</math>

Where:

<math>v</math> = The [[speed]] of [[sound]] through that [[medium]].

<math>\frac{t}{2}</math> = The [[time]] taken for the [[sound]] to travel to the [[object]] or from the [[object]] back to the detector.

<math>x</math> = The [[distance]] between the [[emitter]] and [[object]].

===Example Calculations===

@@ Line 17: / Line 17: @@
 *Dolphins - To locate [[prey]] and the size and shape of their surroundings.
 *Boats - To find shoals of [[fish]] and to find the distance to the sea bed.
-*Submarines - To navigate underwater detecting the sea bed and to locate [[ship]]s.
+*Submarines - To navigate underwater detecting the sea bed and to locate ships.
 ===Equation===

@@ Line 39: / Line 39: @@
 {| class="wikitable"
 | style="height:20px; width:300px; text-align:center;" |A fishing boat uses sonar to detect schools of fish beneath the boat. A sonar pulse is emitted and then received 0.042 [[second]]s later. The [[speed]] of [[sound]] in [[water]] is 1500m/s. Calculate how far beneath the boat the school of fish is located, correct to two [[Significant Figures|significant figures]].
-| style="height:20px; width:300px; text-align:center;" |A bat uses sonar to locate its [[prey]]. The bat emits an [[ultrasound]] squeak which it hears [[reflect]]ed off its [[prey]] 30ms later. The [[speed]] of [[sound]] in [[air]] is 340m/s. Calculate the distance to the [[bat]]s [[prey]], correct to two [[Significant Figures|significant figures]].
+| style="height:20px; width:300px; text-align:center;" |A bat uses sonar to locate its [[prey]]. The bat emits an [[ultrasound]] squeak which it hears [[reflect]]ed off its [[prey]] 30ms later. The [[speed]] of [[sound]] in [[air]] is 340m/s. Calculate the distance to the bats [[prey]], correct to two [[Significant Figures|significant figures]].
 |-
 | style="height:20px; width:300px; text-align:left;" |'''1. State the known quantities'''

@@ Line 14: / Line 14: @@
 [[Echolocation]] is used by:
-*[[Bat]]s - To avoid obstacles when flying and to find [[prey]].
+*Bats - To avoid obstacles when flying and to find [[prey]].
-*[[Dolphin]]s - To locate [[prey]] and the size and shape of their surroundings.
+*Dolphins - To locate [[prey]] and the size and shape of their surroundings.
-*[[Boat]]s - To find shoals of [[fish]] and to find the distance to the sea bed.
+*Boats - To find shoals of [[fish]] and to find the distance to the sea bed.
-*[[Submarine]]s - To navigate underwater detecting the sea bed and to locate [[ship]]s.
+*Submarines - To navigate underwater detecting the sea bed and to locate [[ship]]s.
 ===Equation===
@@ Line 34: / Line 34: @@
 <math>\frac{t}{2}</math> = The [[time]] taken for the [[sound]] to travel to the [[object]] or from the [[object]] back to the detector.
-<math>x</math> = The [[distance]] between the [[emitter]] and [[object]].
+<math>x</math> = The [[distance]] between the [[emit]]ter and [[object]].
 ===Example Calculations===
 {| class="wikitable"
 | style="height:20px; width:300px; text-align:center;" |A fishing boat uses sonar to detect schools of fish beneath the boat. A sonar pulse is emitted and then received 0.042 [[second]]s later. The [[speed]] of [[sound]] in [[water]] is 1500m/s. Calculate how far beneath the boat the school of fish is located, correct to two [[Significant Figures|significant figures]].
-| style="height:20px; width:300px; text-align:center;" |A [[bat]] uses sonar to locate its [[prey]]. The [[bat]] emits an [[ultrasound]] squeak which it hears [[reflect]]ed off its [[prey]] 30ms later. The [[speed]] of [[sound]] in [[air]] is 340m/s. Calculate the distance to the [[bat]]s [[prey]], correct to two [[Significant Figures|significant figures]].
+| style="height:20px; width:300px; text-align:center;" |A bat uses sonar to locate its [[prey]]. The bat emits an [[ultrasound]] squeak which it hears [[reflect]]ed off its [[prey]] 30ms later. The [[speed]] of [[sound]] in [[air]] is 340m/s. Calculate the distance to the [[bat]]s [[prey]], correct to two [[Significant Figures|significant figures]].
 |-
 | style="height:20px; width:300px; text-align:left;" |'''1. State the known quantities'''

@@ Line 38: / Line 38: @@
 ===Example Calculations===
 {| class="wikitable"
-| style="height:20px; width:300px; text-align:center;" |A fishing boat uses [[sonar]] to detect schools of fish beneath the boat. A sonar pulse is emitted and then received 0.042 [[second]]s later. The [[speed]] of [[sound]] in [[water]] is 1500m/s. Calculate how far beneath the boat the school of fish is located, correct to two [[Significant Figures|significant figures]].
+| style="height:20px; width:300px; text-align:center;" |A fishing boat uses sonar to detect schools of fish beneath the boat. A sonar pulse is emitted and then received 0.042 [[second]]s later. The [[speed]] of [[sound]] in [[water]] is 1500m/s. Calculate how far beneath the boat the school of fish is located, correct to two [[Significant Figures|significant figures]].
-| style="height:20px; width:300px; text-align:center;" |A [[bat]] uses [[sonar]] to locate its [[prey]]. The [[bat]] emits an [[ultrasound]] squeak which it hears [[reflect]]ed off its [[prey]] 30ms later. The [[speed]] of [[sound]] in [[air]] is 340m/s. Calculate the distance to the [[bat]]s [[prey]], correct to two [[Significant Figures|significant figures]].
+| style="height:20px; width:300px; text-align:center;" |A [[bat]] uses sonar to locate its [[prey]]. The [[bat]] emits an [[ultrasound]] squeak which it hears [[reflect]]ed off its [[prey]] 30ms later. The [[speed]] of [[sound]] in [[air]] is 340m/s. Calculate the distance to the [[bat]]s [[prey]], correct to two [[Significant Figures|significant figures]].
 |-
 | style="height:20px; width:300px; text-align:left;" |'''1. State the known quantities'''

@@ Line 44: / Line 44: @@
 v = 1500m/s
-t = 0.042
+t = 0.042s
 | style="height:20px; width:300px; text-align:left;" |'''1. State the known quantities'''

@@ Line 28: / Line 28: @@
 <math>x = v \frac{t}{2}</math>
-Where:
+Where
 <math>v</math> = The [[speed]] of [[sound]] through that [[medium]].

@@ Line 11: / Line 11: @@
 #The [[sound]] is detected.
 : The time it takes the [[sound]] to return to its source can show how far away the [[object]] is located. Since the [[sound]] has to travel to the [[object]] and back again this time is twice as long as the time taken just to travel to the [[object]].
-: An [[object]] can be made 'invisible' to [[echolocation]] if it [[Absorb (Physics)absorbs]] the [[sound]] instead of [[reflect]]ing it.
+: An [[object]] can be made 'invisible' to [[echolocation]] if it [[Absorb (Physics)|absorbs]] the [[sound]] instead of [[reflect]]ing it.
 [[Echolocation]] is used by:

← Older revision		Revision as of 18:37, 19 February 2019
Line 36:		Line 36:

	===Example Calculations===		===Example Calculations===
		+	{\| class="wikitable"
		+	\| style="height:20px; width:300px; text-align:center;" \|A fishing boat uses [[sonar]] to detect schools of fish beneath the boat. A sonar pulse is emitted and then received 0.042 [[second]]s later. The [[speed]] of [[sound]] in [[water]] is 1500m/s. Calculate how far beneath the boat the school of fish is located, correct to two [[Significant Figures\|significant figures]].
		+	\| style="height:20px; width:300px; text-align:center;" \|A [[bat]] uses [[sonar]] to locate its [[prey]]. The [[bat]] emits an [[ultrasound]] squeak which it hears [[reflect]]ed off its [[prey]] 30ms later. The [[speed]] of [[sound]] in [[air]] is 340m/s. Calculate the distance to the [[bat]]s [[prey]], correct to two [[Significant Figures\|significant figures]].
		+	\|-
		+	\| style="height:20px; width:300px; text-align:left;" \|'''1. State the known quantities'''
		+
		+	v = 1500m/s
		+
		+	t = 0.042
		+	\| style="height:20px; width:300px; text-align:left;" \|'''1. State the known quantities'''
		+
		+	v = 340m/s
		+
		+	t = 30ms = 30x10<sup>-3</sup>s
		+	\|-
		+	\| style="height:20px; width:300px; text-align:left;" \|'''2. [[Substitute (Maths)\|Substitute]] the numbers into the [[equation]] and [[Solve (Maths)\|solve]].'''
		+
		+	<math>x = v \frac{t}{2}</math>
		+
		+	<math>x = 1500 \frac{0.042}{2}</math>
		+
		+	<math>x = 31.5m</math>
		+
		+	<math>x \approx 32m</math>
		+
		+	\| style="height:20px; width:300px; text-align:left;" \|'''2. [[Substitute (Maths)\|Substitute]] the numbers into the [[equation]] and [[Solve (Maths)\|solve]].'''
		+
		+	<math>x = v \frac{t}{2}</math>
		+
		+	<math>x = 340 \frac{30 \times 10^{-3}}{2}</math>
		+
		+	<math>x = 5.1m</math>
		+	\|}