Get premium membership and access questions with answers, video lessons as well as revision papers.
V = f x wavelength = 20000Hz x 0.075m = 1500 but V = $\frac{d}{t}$ = $\frac{2d}{3}$ (echo)$\rightarrow$ 2d = 4500 $\rightarrow$ d = 2250 m
johnmulu answered the question on February 11, 2017 at 08:44
- The wavelength of a radio wave is 1 km. Determine its frequency.(Solved)
The wavelength of a radio wave is 1 km. Determine its frequency.
(Take the speed of light as 3.0 X 108ms-1)
Date posted: February 11, 2017. Answers (1)
- State difference between mechanical and electromagnetic waves(Solved)
State difference between mechanical and electromagnetic waves.
Date posted: February 11, 2017. Answers (1)
- The audible frequency range for a certain person is 30 Hz and 16, 500 Hz. Determine the largest wavelength of sound in air the person can detect(Solved)
The audible frequency range for a certain person is 30 Hz and 16, 500 Hz. Determine the largest wavelength of sound in air the person can detect.
(Speed of sound in air = 330m/s)
Date posted: February 11, 2017. Answers (1)
- Water waves are observed as they pass a fixed point at a rate of 30 crests per minute. A particular wave crest takes 2s to travel between two fixed points 6m apart.(Solved)
Water waves are observed as they pass a fixed point at a rate of 30 crests per minute. A particular wave crest takes 2s to travel between two fixed points 6m apart.
Determine for the wave:
i) The frequency
ii) The wavelength
Date posted: February 11, 2017. Answers (1)
- Give one example of a transverse wave and one example of longitudinal wave(Solved)
Give one example of a transverse wave and one example of longitudinal wave
Date posted: February 11, 2017. Answers (1)
- Calculate the wavelength of the KBC FM radio wave transmitted at a frequency of 95.6 Mega Hertz(Solved)
Calculate the wavelength of the KBC FM radio wave transmitted at a frequency of 95.6 Mega Hertz.
Date posted: February 11, 2017. Answers (1)
- State two distinctions between the way sound waves and electromagnetic waves are transmitted(Solved)
State two distinctions between the way sound waves and electromagnetic waves are transmitted.
Date posted: February 11, 2017. Answers (1)
- What is the difference between longitudinal and transverse waves?(Solved)
What is the difference between longitudinal and transverse waves?
Date posted: February 11, 2017. Answers (1)
- A spring extends by 6 cm when supporting a mass of 0.06 kg on earth. When the spring is used to support the same mass on the moon, it extends by 1 cm(Solved)
A spring extends by 6 cm when supporting a mass of 0.06 kg on earth. When the spring is used to support the same mass on the moon, it extends by 1 cm. Determine the moon's gravitational strength. (Take gravitational field strength on earth as 10 Nkg-1)
Date posted: February 11, 2017. Answers (1)
- A light spiral extends by 4 mm when loaded with a weight W. The spring is connected in series with an identical spring(Solved)
A light spiral extends by 4 mm when loaded with a weight W. The spring is connected in series with an identical spring. The combination is loaded with the weight W. Determine the extension of the combination.
Date posted: February 11, 2017. Answers (1)
- An object of weight 20 N attached at the end of a spring causes an extension of 0.5 cm on the spring(Solved)
An object of weight 20 N attached at the end of a spring causes an extension of 0.5 cm on the spring.
a) Determine the spring constant of the spring
b) Determine the weight of an object that would cause an extension of 0.86 cm when attached at the end of the same spring
Date posted: February 11, 2017. Answers (1)
- State the SI unit of a spring constant(Solved)
State the SI unit of a spring constant.
Date posted: February 11, 2017. Answers (1)
- You are provided with two wires of same material and same thickness. Describe how would make two spiral springs of different springs constants(Solved)
You are provided with two wires of same material and same thickness. Describe how would make two spiral springs of different springs constants (assume that other apparatus to make springs are available)
Date posted: February 11, 2017. Answers (1)
- State Hooke's law(Solved)
State Hooke's law.
Date posted: February 11, 2017. Answers (1)
- A wire fixed at one end extends by 4mm when a load of 20N is suspended from the other end. Determine the load that would cause an extension of 1.5 mm on the wire(Solved)
A wire fixed at one end extends by 4mm when a load of 20N is suspended from the other end. Determine the load that would cause an extension of 1.5 mm on the wire. (Assume elastic limit is not exceeded)
Date posted: February 11, 2017. Answers (1)
- State two ways in which the strength of an electromagnet can be increased(Solved)
State two ways in which the strength of an electromagnet can be increased.
Date posted: February 11, 2017. Answers (1)
- An electromagnet is made by winding insulated copper wire on an iron core. State two changes that could be made to increase the strength of the electromagnet(Solved)
An electromagnet is made by winding insulated copper wire on an iron core. State two changes that could be made to increase the strength of the electromagnet.
Date posted: February 11, 2017. Answers (1)
- State two ways of increasing the force on the coil(Solved)
State two ways of increasing the force on the coil.
Date posted: February 11, 2017. Answers (1)
- Why is the core of the electromagnet of an electric bell made of soft iron and not steel?(Solved)
Give reason why the core of the electromagnet of an electric bell is made of soft iron and not steel.
Date posted: February 11, 2017. Answers (1)
- State two factors that affect the strength of an electromagnet(Solved)
State two factors that affect the strength of an electromagnet.
Date posted: February 11, 2017. Answers (1)