What is example of negative work? Negative work follows when the force has a component opposite or against the displacement. Negative work removes or dissipates energy from the system. Two examples: In pulling a box of books along a rough floor at constant velocity, I do positive work on the box, that is I put […]
Where do we use concave and convex mirrors?
Where do we use concave and convex mirrors? Concave mirror is used by dentist, solar furnace, reflector of a torch, etc. Convex mirror is used in rear view mirrors. What do concave and convex mirrors have in common? Similarities between lenses and mirrors A convex lens acts a lot like a concave mirror. Both converge […]
What is the relationship between the kinetic energy of an object?
What is the relationship between the kinetic energy of an object? Kinetic energy is directly proportional to the mass of the object and to the square of its velocity: K.E. = 1/2 m v2. If the mass has units of kilograms and the velocity of meters per second, the kinetic energy has units of kilograms-meters […]
What to do if you are being spied on?
What are the signs of a timing belt going bad?
What is the role of second messenger in hormone action?
What is the role of second messenger in hormone action? Second messengers are molecules that relay signals received at receptors on the cell surface — such as the arrival of protein hormones, growth factors, etc. But in addition to their job as relay molecules, second messengers serve to greatly amplify the strength of the signal. […]
Are orbits stable?
Are orbits stable? Although the numerical simulations all indicate chaos in planetary orbits, in a qualitative sense the planetary orbits are stable—because the planets remain near their present orbits—over the lifetime of the sun. What happens if a satellite slows down? If the satellite slows down it would crash into the object it is orbiting. […]
What happens if we drink expired beer?
What happens if we drink expired beer? Expired alcohol doesn’t make you sick. If you drink liquor after it’s been open for more than a year, you generally only risk a duller taste. Flat beer typically tastes off and may upset your stomach, whereas spoiled wine usually tastes vinegary or nutty but isn’t harmful. Can […]
What is the goal of a psychologist?
What is the goal of a psychologist? In the broadest of terms, a psychologist’s goal is to study and treat people who have mental illnesses or emotional difficulties, or to provide research on human behavior and how people think. There are three main types of psychologists – research, counseling and applied – and many specializations. […]
Does voltage change when resistance increases?
Does voltage change when resistance increases? As long as the power supply stays constant when resistance is added voltage will increase. If we increase the value in ohms of the resistor, the voltage across the battery terminal and the resistor remains the same. However, due to the increased resistance, we now have less current flowing […]