Category: Physics

How old is the sunlight we see today? 170 000 years Can we see in the past? We are seeing into the past too. While sound travels about a kilometre every three seconds, light travels 300,000 kilometres every second. When we see a flash of lighting three kilometres away, we are seeing something that happened […]

What is the difference between a dependent and independent t test? The independent samples t-test compares two independent groups of observations or measurements on a single characteristic. The independent samples t-test is the between-subjects analog to the dependent samples t-test, which is used when the study involves a repeated measurement (e.g., pretest vs. How do […]

Why are beta particles dangerous? Radioactive material that emits alpha particles (alpha emitters) can be very harmful when inhaled, swallowed, or absorbed into the blood stream through wounds. Beta particles: Beta particles are capable of penetrating the skin and causing radiation damage, such as skin burns. Which is more ionizing alpha or beta? Because of […]

Why do passengers fall backwards when they start suddenly? When the bus starts moving suddenly, the lower part of the body of passengers, which is in contact with the bus, come in motion, but upper part of their body tends to be in the state of rest and the passengers fall backward. Why is it […]

Why is the galaxy spiral shape? Astronomers believe that galaxies have spiral arms because galaxies rotate – or spin around a central axis – and because of something called “density waves.” A spiral galaxy’s rotation, or spin, bends the waves into spirals. Stars pass through the wave as they orbit the galaxy center. What shape […]

How do you contain sound? Steps Install sound curtains or thick blankets. You can absorb a little sound by mounting thick blankets to the wall. Use bookcases. You can make walls thicker and more soundproofed by simply making use of bookshelves. Mount shaky items. Install a door sweep. Use acoustic wedges panels. How can I […]

What are the three main causes of the Dust Bowl? What circumstances conspired to cause the Dust Bowl? Economic depression coupled with extended drought, unusually high temperatures, poor agricultural practices and the resulting wind erosion all contributed to making the Dust Bowl. The seeds of the Dust Bowl may have been sowed during the early […]

Are force and acceleration directly proportional? As we increase the force on an object the acceleration increases proportionally. Since the mass does not change as the acceleration increases, we can say that force is equal to acceleration. Force is directly proportional to acceleration (force ~ acceleration) As force increases acceleration increases. What is the exact […]

What are two types of natural resources? Natural resources are substances that occur naturally. They can be sorted into two categories: biotic and abiotic. Biotic resources are gathered from the biosphere or may be grown. Abiotic resources are non-living, like minerals and metals. How do we protect natural resources? Ten Simple Things You Can Do […]

Does drinking water make you colder? Hot drinks can actually make you cool down. This is because when you drink a hot drink, there is often a big increase in the amount you sweat. Sweat may seem like a pain – but it’s actually the body’s primary method of cooling you down. Why do we […]