Why must we measuring blood pressure at the arm?
Blood pressure is normally measured with the cuff of the sphygmomanometer around the arm. Suppose the blood pressure were measured with the cuff around the calf of the leg of…
Why an orchestra needs to be warmed up first?
Question: If an orchestra doesn’t warm up before a performance, the strings go flat and the wind instruments go sharp during the performance. Why? Answer: Without warming up, all the…
Why can’t you skate on glass?
Question: Glass is smoother than ice. Yet, why is it you can skate on ice and not on glass? Answer: Ice melts under pressure. So, when the steel blades…
Why using a fan will make ice melt faster?
Question: A fan cools you on a hot day. Yet, why does the same fan warm an ice to make it melt faster? Answer: Air from a fan is not…
Does the water level rises when an ice cube is melted?
Question: A cube of ice floats in a glass of water, the entire system at 0°C. Just enough heat is supplied to melt the ice cube without altering the system’s…
Why air doesn’t crush us?
Question: Air is heavy enough to crush us, but why doesn’t it? Why do we often make the mistake of thinking air weighs nothing? Answer: Air is very heavy….