Question

True/False
Indicate whether the statement is true or false by circling one of the letters

T / F 40. Materials that are poor heat conductors are insulators.
T / F 41. Heat transfer by means of atoms moving from one place to another is conduction.
T / F 42. Winds and weather patterns are good examples of radiation currents.
T / F 43. When steam changes to liquid water at 100°C, energy is released from the water.
T / F 44. Air high in the atmosphere that plunges downward (where pressure increases) tends to cool.
T / F 45. Sound can travel through solids, liquids, gases, and even a vacuum.
T / F 46. In order for sound from a speaker to reach a listener, air near the speaker must travel to the listener.
T / F 47. The word "pitch" refers to the period of a sound wave.
T / F 48. When an object is forced to vibrate at its natural frequency, its vibration amplitude increases.
T / F 49. Light sometimes acts as a wave and sometimes as a particle.
T / F 50. The eye contains a converging lens that focuses light.
T / F 51. If an object displaces its weight worth of a fluid, it will float in that fluid.

Answer 1

40. true

41. true

42.false , they are example of convection current.

43. true, heat is absobed by water when steam is converted into water which increase the internal energy.

44. false, with increase in pressure it will ten to be hot.

45. false, sound waves cannot travel through vaccum.

46. false, sound travels through vibfration of molecules not by motion of molecules.

47.false. it refers to frequency of sound wave and is inversely proportional to time period.

48.true.

49.true.light has dual nature

50. true

51. true