Answer:
Explanation:
The heat received by water is equal to the heat rejected by the piece of metal. That is to say:
The initial temperature of the piece of metal is:
69. The student's skin was obviously warmer than the initial temperature of the bracelet. According to the second law of thermodynamics, heat transfers from a higher temperature to a lower temperature hence heat transfers from the student's skin to the bracelet warming up the bracelet.
70. moles of copper=mass of copper/molar mass of copper
=30.1g/(63.55g/mol)= 0.4736 moles Cu
71. Delta H( heat released) = mCp(deltaT) = 30.1g(0.385 J/gK)(33-19)K = 162.23J
72. Copper is chemically less active than iron.
Answer 1) : To rank the species according to the decreasing energy needed to raise the temperature of 10 g of the substance by 25 °C, the oder of energy needed is given below as per their specific heat.
Which requires more energy as per their specific heats;
- water 4.184
- aluminum 0.897
- cast iron 0.460
- Copper 0.385
- Silver 0.235
Answer 2)To rank items as equivalent, overlap them.
The average kinetic energy of the molecules after point D,
The average kinetic energy of the molecules from point B to point C,
The average kinetic energy of the molecules before point A.
Answer:
Change in height of the object
Explanation:
Change in height of the object
Since ,
We know potential energy can be written as mgh where
P.E. = mgh
M = mass ,
g = gravity constant
h = height
Kinetic energy can be written as 0.5 mv²
So , the Potential energy = kinetic energy
Then ,
velocity of object = √2 gh
Since g is a constant ,
Hence ,
Height of object will determine the velocity.
