0This is the foremost important physics topic. Students very often than not forget Conversion of Units of physical quantities to one system while solving numerical questions. This leads to wrong answers and failure in competitive exams. Such errors or failures also cause disaster in real life making the society pay a very heavy price.
Physics is fundamentally an empirical science. Measurements, units & uncertainties are at the heart of it. All laws of nature are derived empirically and expressed by mathematical equations. How otherwise scientists can express relationships between measurable physical quantities? It is equally vital to express the measurement in right unit; else invite disaster.
The Mars Climate Orbiter costing about US$ 125 million came to a catastrophic conclusion because of confusion in UNITS. One engineering team used Metric Units while another team used English Units. As a result in September 1999 the spacecraft entered Martian atmosphere instead of reaching a stable orbit.
Equally important is Uncertainties in measurements e.g. pair of pants of size 34 that varies just 3 percent changes a full inch in waist size. It could end up a 35 and hang on the hips or a 33 making you wonder how you gained all that weight.
Measurements, Units and Uncertainties are crucially important and when properly implemented can create wonders in Life (and also exams); else a disaster. Students should pay utmost importance to Units, Conversion of Units and Uncertainties.
