abhirsoman89

The horizontal and vertical components of velocity for a projectile __________.

1. Always remain constant

2. Horizontal decreases but vertical increases with time

3. Horizontal remains constant but vertical changes with time

4. Both increase with time

During a phase change the temperature of a substance

1. Increase

2. Deceases

3. Remains constant

4. Changes indefinitely

3. Explain why, for a gas, the specific heat at constant volume has a different value 
from the specific heat at constant pressure.
An ideal gas is contained in a cylinder fitted with a piston. Initially the temperature of the 
gas is 15℃. If the mass of the gas is 0.035 kg, calculate the quantity of heat energy 
required to raise the temperature of the gas to 150 ℃ when:
(a) The piston is fixed;
(b) The piston moves and the pressure is constant.
For the gas, 𝑐𝑣 = 676 J/kg-K and 𝑐𝑝 = 925 J/kg-K.

1. A piston–cylinder device initially contains 0.82 m3 of air at 212 kPa and 78.2oC. The air is now compressed to 0.47 m3 in such a way that the temperature inside the cylinder remains constant. Determine the work done during this process ΔW , the pressure P and density Δ at the terminal process state. Take for air: Rg=287.0 J/(kg K), Cp=1005 J/(kg K), Cv= 718 J/(kg K), k=1.4.

1. Calculate the quantity of heat energy which must be transferred to 2.25 kg of brass to 
raise its temperature from 20 ℃ to 240 ℃ if the specific heat of brass is 394 J.kg-K.

2. Find the change in temperature produced by 10 kJ of heat energy added to 500 g 
copper. Specific heat of copper 0.39 kJ/kg-K.

3. Explain why, for a gas, the specific heat at constant volume has a different value 
from the specific heat at constant pressure.
An ideal gas is contained in a cylinder fitted with a piston. Initially the temperature of the 
gas is 15℃. If the mass of the gas is 0.035 kg, calculate the quantity of heat energy 
required to raise the temperature of the gas to 150 ℃ when:
(a) The piston is fixed;
(b) The piston moves and the pressure is constant.
For the gas, 𝑐𝑣 = 676 J/kg-K and 𝑐𝑝 = 925 J/kg-K.