Which of the following statements about sound is NOT true?
sound is a longitudinal wave
sound can be reflected and refracted like light
sound travels through a vacuum
sound moves faster in a steel wire than in air
sound can ony be produced by vibrating objects
Correct answer is C
Sound cannot travel through a vacuum. A vacuum is an area without any air, like space. So sound cannot travel through space because there is no matter for the vibrations to work in.
If the volume of a fixed mass of a gas is kept constant, the pressure of the gas
is inversely proprotional to its centigrade temperature
is inversely proportional to its absolute temperature
is directly proportional to its centigrade temperature
is directly proportional to its absolute temperature
remains constant also
Correct answer is D
Gay-Lussac's Law states that the pressure of a given mass of gas varies directly with the absolute temperature of the gas, when the volume is kept constant.
the temperature rises and the ice expands
the temperature remains constant and the volume of ice decreases
the ice gives out heat as it melts
the mass remains constant and the temperature increases
the mass decreases because some heat is lost to the atmosphere
Correct answer is B
No explanation has been provided for this answer.
mg
(m + pv)g
(m - pv)g
pvg
[M/m-pv]g
Correct answer is C
Tension = upthrust on object
= weight in air - weight i liga
= mg - pvg
= (m - pv)g