Blog

A circular hole in a copper plate is 3.925 cm in diameter at 30.0 °C.  What is the diameter of the hole if the temperature of the plate is raised to 150.0 °C?  The coefficient of linear expansion of copper is 17 × 10–6/C°. 

A heat engine is used to lift a 3000-kg load to a height of 4 m at a constant speed. During the lifting process, the engine received 500,000 J of heat from the fuel burned in its interior. What is the efficiency of the engine?

Water is flowing through a pipeline at the speed of 5 m/s when it encounters a vertical bend in the pipe raising it by 4.0 m. After the rise, the speed of flow reduces to 4 m/s. The cross-sectional area of the pipe does not change. What is the difference in pressure (PB – PA) in the portions of the pipe before and after the rise?  

In a well-insulated container, 4.0 kg of water and 3.0 kg of ice are in thermal equilibrium at 0 °C. How much heat is required to bring the system to thermal equilibrium at 45 °C?

A rock weighs 20 N in air and 15 N when completely submerged in a fluid with a density of 800 kg/m3.   Determine the density of the rock.

Water enters a pipe of diameter 5 cm with a velocity of 4 m/s. Then the water encounters a constriction and its velocity becomes 16 m/s. What is the diameter of the constricted portion of the pipe?

A student does 1500 J of work while studying.  In the process, her internal energy decreases by 2600 J.  Determine the value of Q, including the algebraic sign.

What is the pressure difference between the street level and the roof of a 300 m high tower?  (Assume the density of air is 1.29 kg/m3 )

A student does 1290 J of work while studying.  In the process, her internal energy decreases by 2490 J.  Determine the value of Q, including the algebraic sign.

Figure 2.1 Using Figure 2.1, match the following:Tertiary (protein) structure.