Facts At Your Fingertips: Energy and forces – Light Light is the only form of electromagnetic radiation we can see. Most things absorb and reflect light, but few objects give out light. The Sun is the main source of light in the day, while electric lights provide illumination at night. Making shadows Some materials, such … Read more
Facts At Your Fingertips: Energy and forces – The EM spectrum Electromagnetic (EM) radiation is a form of energy that travels in waves at a speed of 186,000 miles (300,000 km) per second, which is the fastest speed in the universe. Different kinds of radiation make up the EM spectrum. All types of radiation except … Read more
Facts At Your Fingertips: Energy and forces – Electromagnetism An electrical current always produces a magnetic field around it. Electromagnets are made by passing electricity through a wire that has been wrapped around a piece of iron. Unlike permanent magnets, an electromagnet loses its magnetism as soon as the electrical current is switched off. How … Read more
Facts At Your Fingertips: Energy and forces – Magnets in action We use magnets in many different ways. The motors inside many machines are driven by small magnets, while large magnets can power trains. Compasses use Earth’s magnetism to show us the way. Electric motors This toy car is powered by an electric motor, which … Read more
Facts At Your Fingertips: Energy and forces – Magnetism Magnetism is a force that can attract (pull toward) or repel (push away). Materials that are strongly attracted to magnets, such as iron or nickel, are called ferromagnetic materials. Some magnets are permanently charged with magnetism, while others are only magnetic when they are inside a … Read more
Facts At Your Fingertips: Energy and forces – Using electricity The electricity we use around our homes and to power our gadgets is produced in several ways. It can be generated in massive power plants located far away. On a smaller scale, items such as flashlights and cell phones can be powered by batteries that … Read more
Facts At Your Fingertips: Energy and forces – Electricity All atoms contain positively charged protons and negatively charged electrons. Electricity is a flow of charged electrons from one place to another. When electrons are transferred between substances, it can cause a buildup of negative charge in one place and positive charge in another— sometimes with … Read more
Facts At Your Fingertips: Energy and forces – Atom power An enormous amount of energy is locked up inside the nucleus of an atom. This can be released by splitting the nucleus apart in a process known as fission. This energy can also be unleashed by fusion, which involves squeezing nuclei together. Nuclear fission To … Read more
Facts At Your Fingertips: Energy and forces – What is energy? Energy is what makes everything happen. It cannot be created or destroyed, but it can be transferred. For example, kicking a ball transfers energy from the person to the ball. Energy can also be converted from one form to another—as when the chemical energy … Read more
Facts At Your Fingertips: Energy and forces Everything in the universe is constantly affected by energy and forces. A roller coaster is a good example of energy and forces in action. Fuel provides the energy needed to generate the force that pulls the roller coaster to the top of the slope. The stored potential energy … Read more
