NECO 2023 PHYSICS SOLUTION
Static friction is the force that resists the motion of two objects that are in contact and are not moving relative to each other. It is the force that must be overcome before an object can start to move.
Static friction = horizontal force / weight
Static friction = 3N / 5N
Static friction = 0.6
The velocity ratio of a machine is the ratio of the velocity of its output to the velocity of its input.
Second order levers have the fulcrum placed between the input and output, WHILE third order levers have the input placed between the fulcrum and output.
PICK ANY TWO(2)
1. Communication: Radio waves, microwaves, and other forms of electromagnetic radiation are used to transmit information over long distances.
2. Electric Motors: Electromagnetic fields are used to generate torque in electric motors.
3. Magnetic Resonance Imaging (MRI): MRI uses strong magnetic fields to create detailed images of the inside of the body.
4. Electric Generators: Electromagnetic fields are used to generate electricity in electric generators.
5. Navigation: Electromagnetic fields are used to determine the position and orientation of objects.
To convert a soft iron bar into a magnet, the bar must be placed in a strong magnetic field. This can be done by stroking the bar with a bar magnet. This process, known as magnetization, aligns the domains of the soft iron bar, making it a magnet.
Photo-electrons are particles of light, or photons, that are emitted when a photon of sufficient energy strikes a material. They are the result of the photoelectric effect, which is the emission of electrons from a material when it is exposed to electromagnetic radiation. Photo-electrons are typically used in photoelectric detectors, which are used to measure the intensity of light.
Threshold frequency = (Work function x 1.6×10^-19 J) / (h x 66×10^-34 Js)
Threshold frequency = (3.5eV x 1.6×10^-19 J) / (66×10^-34 Js)
Threshold frequency = 2.27×10^14 Hz
Pick any two(2)
1. Radiation Exposure: X-rays are a form of ionizing radiation, which can cause damage to living tissue, including skin and organs.
2. Cancer Risk: Long-term exposure to X-rays increases the risk of developing cancer.
3. Skin Burns: X-rays can cause skin burns if the patient is exposed to too much radiation.
4. Pregnancy Risk: Exposure to X-rays during pregnancy may cause birth defects or other health problems in the baby.
5. Eye Damage: X-rays can cause eye damage, including cataracts and other vision problems.
Soft X-rays have a lower energy and shorter wavelength *than* hard X-rays. Soft X-rays are typically used in medical imaging, such as X-ray imaging of the chest and abdomen. Hard X-rays have a higher energy and longer wavelength than soft X-rays. Hard X-rays are typically used in industrial applications, such as inspecting welds and other materials.