Category: Physics

Why do the bullet fired horizontally and the bullet dropped hit the ground at the same time? The fired bullet only experiences a horizontal force from the gun. The only vertical force acting on the fired bullet is gravity. Therefore, the fired bullet and the dropped bullet both experience the same exact downward force. This […]

What is the IQ rating scale? IQ tests are made to have an average score of 100. Most people (about 68 percent) have an IQ between 85 and 115. Only a small fraction of people have a very low IQ (below 70) or a very high IQ (above 130). The average IQ in the United […]

What is homeostasis in cells? In biology, homeostasis is the state of steady internal, physical, and chemical conditions maintained by living systems. This is the condition of optimal functioning for the organism and includes many variables, such as body temperature and fluid balance, being kept within certain pre-set limits (homeostatic range). What is homeostatic imbalance […]

What protects the cell and is selectively permeable? A selectively permeable (sometimes called semi-permeable) membrane allows some molecules across but not others. JOB: The cell membrane controls what enters and exits the cell and thus protects the cell. How do organelles help keep the cell alive? Core organelles are found in virtually all eukaryotic cells. […]

What will happen when a force is applied on a moving object against the direction of motion? If the force applied on the object is in the direction of its motion, the speed of the object increases. If the force is applied in the direction opposite to the direction of motion, then it results in […]

What is light quality? Light quality is the wavelength (in nanometers, nm) within the electromagnetic spectrum; i.e. blue light is 450 nm and red light is 650 nm. Each wavelength has a different packet of radiation or energy (in J mol-1) called photons. What type of light causes damage to plants? UV-B radiation has been […]

Was the Ark bigger than the Titanic? As you will soon see, conditions were not ideal. We know that the ark was bigger than a rowboat, but smaller than the Titanic. In fact, we know its exact size – it was 450 x 45 x 75 feet, with an approximate volume of 1,518,750 cubic feet. […]

Is it cruel not to walk your dog? Walking your dog is essential for their health, but not doing it doesn’t make you cruel. You might never do dog walks but instead, spend time together and perform other exercises. Is a 20 minute walk enough for a dog? They have moderate exercise needs with a […]

Why do a chicken embryo and a cow embryo look very? Why do a chicken embryo and a cow embryo look very similar even though the adults do not? The embryos mutate in utero to form different structures. The genetic makeup of the two species is similar. What evidence of evolution do we use to […]

What is an ideal weight? Body mass index (BMI) is a common tool for deciding whether a person has an appropriate body weight. It measures a person’s weight in relation to their height. According to the National Institutes of Health (NIH) : A BMI of less than 18.5 means that a person is underweight. A […]