Answer:
14.1 kg
Explanation:
Given:
Length=7.00inches
Width=3.63 inches
Height=1.75 inches
density = 19,300 kg/m3.
We can convert the given parameters to metre for unit consistency
But we know 1 inches= 0.0254 metre
✓Then Length l=7.00inches
=7×0.0254 metre=0.1778m
✓Width w =3.63 inches
==3.63 ×0.0254 metre=0.092m
✓Height h =1.75 inches
=1.75 ×0.0254 metre=0.0445 m
But Mass= density × volume
Volume= Length× width×height
Mass= density× Length× width×height
= 19300kg/m³×0.1778×0.0922×0.0445
=14.1 kg
Therefore, the mass of the gold bar is 14.1 kg
Answer:
potential energy is the ability to do work
Answer:
Option B and Option D are true
Explanation:
We are given;
Number of atoms in block A = 800
Energy content in block A = 20 quanta
Number of atoms in block B = 200
Energy content in block B = 80 quanta
The energy of a system which is an extensive quantity,depends on the mass or number of moles of the system. However, at equilibrium, the energy density of the two copper blocks will be equal. That is, each atom of Cu in the two blocks will, on average, have the same energy. Because block A has 4 times more atoms than block B, it will have 4 times more quanta of energy. Thus, option B is therefore true while option A is false.
Temperature is a measure of the average kinetic energy of the atoms in a material. Now, if each atom in blocks A and B have the same average energy, then the temperatures of blocks A and B will be equal at equilibrium. Thus, option D is true.
Entropy of a system is an extensive quantity that depends on the the mass or number of atoms in the system. Because block A is bigger than block B, it will have higher entropy. However, that the specific entropy (the entropy per mole or per unit mass) is an intensive quantity -- it is independent of the size of a system. The molar entropy of blocks A and B are equal at equilibrium. Thus option C is false.
Answer:
Pressure is the force applied perpendicular to the surface of an object per unit area over which that force is distributed
Unit: Pascal (Pa)
1Pa = 1N/m^2
Answer:
160790 J
Explanation:
We can find the heat necessary for the ice to go from -20 degrees Celsius to 0 degrees Celsius:

Where
is the specific heat of ice, that is the amount of heat that must be supplied per unit mass to raise its temperature in a unit.

We must calculate the latent heat of fusion required for this ice mass to change to water:

Where H=334 J/g is the specific latent heat of fusion of water, that is the amount of energy needed per unit mass of a substance at its melting point to change from the solid to the liquid state.

Then we calculate the heat necessary for the water to go from 0 degrees Celsius to 20 degrees Celsius:

Where
is the specific heat of water, that is the amount of heat that must be supplied per unit mass to raise its temperature in a unit.

Finally the 3 results are added:
