Year 9 Science - Heat And Sound

Sound is produced by vibrations. When an object vibrates, it creates sound waves that travel through the air or other mediums. These sound waves then reach our ears, which interpret them as sound. Therefore, the statement "Sound is produced by vibrations" is true.

Sound waves are longitudinal waves because they propagate by compressing and expanding the medium through which they travel. In other words, the particles of the medium vibrate parallel to the direction of the wave propagation. This is in contrast to transverse waves, where the particles move perpendicular to the direction of the wave.

Sound waves are longitudinal waves because they propagate by compressing and rarefying the medium through which they travel. In other words, the particles of the medium vibrate parallel to the direction of the wave propagation. This is in contrast to transverse waves, where the particles oscillate perpendicular to the direction of wave propagation.

A cochlear implant is a medical device that is surgically implanted in the ear to help individuals with severe hearing loss or deafness. It works by converting sounds into electrical impulses that can be interpreted by the brain. These electrical impulses are sent directly to the auditory nerve, bypassing the damaged parts of the ear. Therefore, the statement "The cochlear implant converts sounds into electrical impulses that are sent to the brain" is true.

Sound waves cannot travel in a vacuum because they require a medium, such as air, water, or solids, to propagate. In a vacuum, there are no particles or molecules to transmit the sound waves, resulting in the absence of sound.

The best insulator among the four types of pool blankets tested is Silverline. This can be inferred from the fact that the temperature at 9 a.m. when using the Silverline pool blanket was 26°C, which is the highest among all the options. This indicates that the Silverline pool blanket was able to trap more heat within the pool and prevent rapid cooling overnight compared to the other blankets.

When an ice-block melts on your hand, the heat is transferred from your hand to the ice-block by conduction. Conduction is the process of heat transfer through direct contact between two objects. In this case, the heat from your hand is conducted to the ice-block, causing it to melt.

The given data shows that the speed of sound increases as the density of the material increases. This can be observed by comparing the speeds of sound in air, water, wood, steel, and glass. Air has the lowest density and the lowest speed of sound, while glass has the highest density and the highest speed of sound. Therefore, it can be concluded that sound travels faster through substances that are more dense.

Sound is a longitudinal wave, which means that its particles vibrate back and forth. This type of wave consists of compressions and rarefactions, where the particles in the medium oscillate parallel to the direction of the wave's propagation. As sound travels through a medium, such as air or water, the particles of the medium vibrate in a back and forth motion, creating the sensation of sound. Therefore, the correct answer is that the particles of sound vibrate back and forth.

The semi-circular canals are responsible for providing us with our sense of balance. These canals are located in the inner ear and are filled with fluid. When we move our head, the fluid in the canals moves as well, stimulating tiny hair cells that send signals to the brain about our body's position and movement. This information helps us maintain our balance and coordinate our movements. The Eustachian tube helps equalize pressure in the middle ear, the oval window transmits sound vibrations to the inner ear, and the pinna is the visible part of the ear that collects sound waves.

The correct answer is 308 K. The Kelvin is the standard SI unit for temperature and is used to measure absolute temperature. To convert degrees Celsius to Kelvin, you simply add 273 to the temperature in degrees Celsius. Therefore, to convert 35°C to Kelvin, you would add 273 to 35, resulting in 308 K.

The question asks for two sounds that have the same amplitude or loudness. Looking at the options, sound A and sound C are the two sounds that have the same amplitude.

The sound with the highest frequency has the shortest wavelength. In this case, sound C has the highest frequency because it is represented by the shortest wavelength.

The correct answer is that the sun transfers its heat energy through radiation, conduction is when heat energy is transferred by vibrating particles, and convection is when heat energy diffuses through a liquid or a gas. This explanation accurately summarizes the main points mentioned in the video.

The correct answer is that different-sized columns of air inside the flute vibrate. When a flute is played, air is blown across the edge of the mouthpiece, creating a stream of air. This stream of air then enters the flute and encounters different-sized columns of air, which are created by the various holes and keys on the flute. As the air passes through these different-sized columns, it causes the air inside the flute to vibrate at different frequencies, producing different notes and creating the sound of the flute.

The video explains that sound is produced when something vibrates. Frequency refers to the number of waves passing a point each second, and the higher the frequency, the higher the pitch or tone of the sound. Amplitude, on the other hand, refers to how loud the sound is.

The time delay between sending and receiving the ultrasound pulse can be calculated by dividing the distance traveled by the speed of sound in water. In this case, the distance traveled is 750 meters and the speed of sound in water is 1500 meters per second. Therefore, the time delay is 750/1500 = 0.5 seconds. However, the question asks for the time delay between sending and receiving the pulse, which means we need to consider the round trip time. So, the actual time delay is twice the one calculated, which is 2 * 0.5 = 1 second.

The given answer is correct because a parka is the most effective insulator, followed by a woollen jumper, a cotton windcheater, and a cotton T-shirt. Insulators work by trapping air and preventing heat transfer. A parka, being a thick and heavily insulated outerwear, is the most effective at trapping air and keeping the body warm. A woollen jumper is also a good insulator due to the natural properties of wool. A cotton windcheater provides some insulation but not as much as a woollen jumper. A cotton T-shirt is the least effective insulator as it does not provide much insulation.

The video explains the process of hearing. It states that sounds are collected by the outer ear and the ear drum vibrates when sound waves strike it. It also mentions that the middle ear contains the hammer, anvil, and stirrup. Additionally, it states that the cochlear is filled with fluid and the tiny hairs in the cochlear transform vibrations into electrical signals that go to the brain.