Answer:
1.84 kJ (kilojoules)
Explanation:
A specific heat of 0.46 J/g Cº means that it takes 0.46 Joules of energy to raise the temperature of 1 gram of iron by 1 Cº.
If we want to heat 50 g of iron from 20° C to 100° C, we can make the following calculation:
Heat = (specific heat)*(mass)*(temp change)
Heat = (0.46 J/g Cº)*(50g)*(100° C - 20° C)
[Note how the units cancel to yield just Joules]
Heat = 1840 Joules, or 1.84 kJ
[Note that the number is positive: Energy is added to the system. If we used cold iron to cool 50g of 100° C water, the temperature change would be (Final - Initial) or (20° C - 100° C). The number is -1.84 kJ: the negative means heat was removed from the system (the iron).
If Juan used a Celsius thermometer, it would tell him the Celsius temperature.
If he added 273 to that number, he'd have the "absolute" or Kelvin temperature.
Answer:


Explanation:
A denotes Alex
M denotes Mary
r = Distance from center
Mary and Alex will have the equal displacements in equal interval of time as they are in uniform circular motion. So,

Tangential speed speed is given by

The tangential speed of Mary is 