Problem: Greg is is a chef. Last night, he was in his kitchen preparing foods for the guests. First, he made some lemonade. In trial one he added some honey in it and stirred it, but in trial two he didn't stir it. Then he made some coffee. In trial three he added hot water in it, but in trial four he added cold water in it. Finally, he made some soup. In trial five he added fine grain salt in it, but in trial six he added coarse salt in it. In which trial the coffee would be prepared faster, trial three or trial four? Hint: When you add sugar to a cold drink, you may stir it to help the sugar dissolve. If you don't stir, the sugar may eventually dissolve, but it will take much longer. Stirring is one of several factors that affect how fast a solute dissolves in a solvent. Temperature is another factor. A solid solute dissolves faster at a higher temperature. For example, sugar dissolves faster in hot tea than in ice tea. A third factor that affects the rate of dissolving is the surface area of the solute. For example, if you put granulated sugar in a glass of ice tea, it will dissolve more quickly than the same amount of sugar in a cube. That's because granulated sugar has much more surface area than a cube of sugar. You can see videos of all three factors at these URLs

A: trial three

Problem: At a doctor's office, two women are having their annual physical done. Jessie goes in first and is told that that she should go see a dermatologist about the skin issues she is having. The doctor then sees Martha who is having a pain in her right arm and who also has hypertension. The doctor talks to Martha about her issues and then heads home for the day. Which woman has a lower blood pressure? Hint: Hypertension , which is also called "high blood pressure," occurs when a person's blood pressure is always high. Hypertension is said to be present when a person's systolic blood pressure is always 140 or higher, and/or if the person's diastolic blood pressure is always 90 or higher. Having hypertension increases a person's chance for developing heart disease, having a stroke, or suffering from other serious cardiovascular diseases. Hypertension often does not have any symptoms, so a person may not know that he or she has high blood pressure. For this reason, hypertension is often called the "silent killer." Treatments for hypertension include diet changes, exercise, and medication. Foods thought to lower blood pressure include skim milk, spinach, beans, bananas and dark chocolate.

A: Jessie

Problem: John and Keith are two friends. They went to see an ophthalmologist for an eye cheek up. The doctor found that John had myopia, but Keith had normal eyes. He advised them according to his findings. Would John's eyeball more likely or less likely be longer than Keith's? Hint: Nearsightedness, or myopia, is the condition in which nearby objects are seen clearly, but distant objects appear blurry. The Figure below shows how it occurs. The eyeball is longer (from front to back) than normal. This causes images to be focused in front of the retina instead of on the retina. Myopia can be corrected with concave lenses. The lenses focus images farther back in the eye, so they fall on the retina instead of in front of it.

A: more likely

Problem: A team of hikers split into two groups. Group Jones hiked north and camped there overnight. Group George went east. Both groups made campfires and heated cans of soups. Group Jones didn't make holes in the cans, so the cans exploded. The others heated their soup cans the right way, by venting them first. Which group's cans had the air molecules inside impact the container walls with less force? Hint: It would be very unadvisable to place a can of soup over a campfire without venting the can. As the can heats up, it may explode. The kinetic-molecular theory explains why. The air inside the rigid can of soup is given more kinetic energy by the heat coming from the campfire. The kinetic energy causes the air molecules to move faster and they impact the container walls more frequently and with more force. The increase in pressure inside may eventually exceed the strength of the can and it will explode. An additional factor is that the soup may begin boiling which will then aid even more gas and more pressure to the inside of the can.

A:
George