Answer: A. Work is done on the system and heat is transferred from the system for a net decrease in internal energy.
Explanation:
A refrigerator is a device which dispenses heat from the close system to a warmer area or in the surrounding. By dispensing the heat the internal temperature of the refrigerator drops. The system of refrigerator violates the second law of thermodynamics. As it performs the work to cool the region instead of heating the region. The work is done on the system and the internal energy decreases and the heat energy is liberated to the surrounding area. A refrigerator is an open system.
Answer: a good level of body fat can be found using your weight and height as a reference.
Explanation:
Answer:
Answered
Explanation:
The radius of curvature of the mirror R = 20 cm
then the focal length f = R/2 = 10 cm
(a) From mirror formula
1/f = 1/di + /1do
then the image distance
di = fd_o / d_o - f
= (10)(40) / 40-10
= 30.76 cm
since the image distance is positive so the image is real
ii) when the object distance d_0=20 cm
di = 10×20/ 20-10
= 20
Hence, the image must be real
iii)when the object distance d_0 = 10
di = 10×10 / 10-10 = ∞ (infinite)
the image will be formed at ∞
here also image will be real but diminished.
Answer:
a) Pb= 200 PA
b).work done= -3600 joules
c).3600joules
D).the system works under isothermal condition so no heat was transferred
Explanation:
2.0 moles of a monatomic ideal gas expands isothermally from state a to state b, Pa = 600 Pa, Va = 3.0 m3, and Vb = 9.0 m3.
a). PbVb= PaVa
Pb= (PaVa)/VB
Pb= (600*3)/9
Pb= 1800/9
Pb= 200 PA
b). work done= n(Pb-Pa)(Vb-Va)
Work done= 2*(200-600)(9-3)
Work done= -600(6)
Work done=- 3600 Pam³
work done= -3600 joules
C). Change in internal energy I the work done on the system
= 3600joules
D).the system works under isothermal condition so no heat was transferred
