Advertisements
Advertisements
प्रश्न
A system releases 130 kJ of heat while 109 kJ of work is done on the system. Calculate the change in internal energy.
Advertisements
उत्तर
Data: Q = −130 kJ, W = −109 kJ
Find: ΔU = ?
Calculations:
ΔU = Q − W
ΔU = −130 − (−109)
ΔU = −130 + 109
ΔU = −21 kJ
∴ The change in internal energy is −21 kJ. This is the change (decrease) in the internal energy.
संबंधित प्रश्न
Explain why Two bodies at different temperatures T1 and T2, if brought in thermal contact, do not necessarily settle to the mean temperature (T1 + T2)/2.
Explain why Air pressure in a car tyre increases during driving.
A force F is applied on a block of mass M. The block is displaced through a distance d in the direction of the force. What is the work done by the force on the block? Does the internal energy change because of this work?
The outer surface of a cylinder containing a gas is rubbed vigorously by a polishing machine. The cylinder and its gas become warm. Is the energy transferred to the gas heat or work?
When we rub our hands they become warm. Have we supplied heat to the hands?
A closed bottle contains some liquid. the bottle is shaken vigorously for 5 minutes. It is found that the temperature of the liquid is increased. Is heat transferred to the liquid? Is work done on the liquid? Neglect expansion on heating.
The final volume of a system is equal to the initial volume in a certain process. Is the work done by the system necessarily zero? Is it necessarily nonzero?
Figure shows two processes A and B on a system. Let ∆Q1 and ∆Q2 be the heat given to the system in processes A and B respectively. Then ____________ .
An ideal gas goes from the state i to the state f as shown in figure. The work done by the gas during the process ______________ .
A 100 kg lock is started with a speed of 2.0 m s−1 on a long, rough belt kept fixed in a horizontal position. The coefficient of kinetic friction between the block and the belt is 0.20. (a) Calculate the change in the internal energy of the block-belt system as the block comes to a stop on the belt. (b) Consider the situation from a frame of reference moving at 2.0 m s−1 along the initial velocity of the block. As seen from this frame, the block is gently put on a moving belt and in due time the block starts moving with the belt at 2.0 m s−1. calculate the increase in the kinetic energy of the block as it stops slipping past the belt. (c) Find the work done in this frame by the external force holding the belt.
A substance is taken through the process abc as shown in figure. If the internal energy of the substance increases by 5000 J and a heat of 2625 cal is given to the system, calculate the value of J.
A gas is initially at a pressure of 100 kPa and its volume is 2.0 m3. Its pressure is kept constant and the volume is changed from 2.0 m3 to 2.5 m3. Its Volume is now kept constant and the pressure is increased from 100 kPa to 200 kPa. The gas is brought back to its initial state, the pressure varying linearly with its volume. (a) Whether the heat is supplied to or extracted from the gas in the complete cycle? (b) How much heat was supplied or extracted?
What is the energy associated with the random, disordered motion of the molecules of a system called as?
Define heat.
What is the internal energy of the system, when the amount of heat Q is added to the system and the system does not do any work during the process?
A system releases 100 kJ of heat while 80 kJ of work is done on the system. Calculate the change in internal energy.
derive the relation between the change in internal energy (∆U), work is done (W), and heat (Q).
An ideal gas is compressed at a constant temperature. Its internal energy will ____________.
In a thermodynamic system, working substance is ideal gas. Its internal energy is in the form of ______.
8 m3 of a gas is heated at the pressure 105 N/m2 until its volume increases by 10%. Then, the external work done by the gas is ____________.
When 1 g of water at 0° C and 1 x 105 N/m2 pressure is converted into ice of volume 1.082 cm3, the external work done will be ____________.
In insulated systems, the amount of external work done by the gas is proportional to:
In thermodynamics, heat and work are ______.
What is heat?
A system releases 125 kJ of heat while 104 kJ work is done on the system. Calculate the change in internal energy.
Explain the change in internal energy of a thermodynamic system (the gas) by heating it.
