The kinetic energy before equals K after
Objects should be cooled before their mass is determined on a sensitive balance because it could damage the balance. Also, because it would give you wrong reading of the mass. Hot objects would warm the air around it. A warm air would expand and would produce convection as it rises causing to give the object a mass that is less than the actual. Another reason would be it would cause instability in the readings, the mass would fluctuate every now and then due to the convection currents around the object. It is always recommended to weigh the masses of objects that are in room temperature.
A.) Electromagnetic Current
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When a woman walks south at a speed of 2.0mph for 60 minutes. She then turns around and walks north at a distance of 3000m in 25 minutes. then the woman's average speed during her entire motion would be 73.15 meters /minute.
<h3>What is speed?</h3>
The total distance covered by any object per unit of time is known as speed.
the mathematical expression for speed is given by
speed = total; distance /total time
As given in the problem a woman walks south at a speed of 2.0mph for 60 minutes
60 min = 1 hour
1 mile = 1.60934 km
The distance covered by her southwards = speed ×time
=2 mph × 60 minutes
= 3.218 km
She then turns around and walks north at a distance of 3000m in 25 minutes
The distance covered northward is 3000m
speed = total distance /total time
=(3218 +3000) /(60+25)
=73.15 meters /minutes
Thus, The average speed of the woman would be 73.15 meters /minute.
Learn more about speed from here
brainly.com/question/13263542
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