In most cases the temperature must increase for thermal expansion to occur. Most substances expand as temperature increases because the atoms or molecules vibrate faster as temperature increases and experience greater separation.
Answer:
it is chemical reactivity (D)
Explanation:
it is because chemical properties are properties that can be measured and observed only when matter undergoes a change to become an entirely different kind of matter.Which they include Chemical reactivity,flammable,and the ability to rust.And Chemical reactivity is the ability of matter to react chemically with other substances.
Answer: :)
1.) The Doppler effect is, the change in sound or light that occurs whenever there is motion between the source and its observer. The siren of the fire engine has a lower pitch as it moves away because the waves are now spread out causing a lower frequency and a lower pitch.
2.) Wave frequency is related to wave energy. Since all that waves really are is traveling energy, the more energy in a wave, the higher its frequency. The lower the frequency is, the less energy in the wave.
The answer:
<span>When the elevator accelerates upward at a rate of 3.6 m/s², the value of the acceleration becomes
</span>A=g+3.6=13.4 m/s²
and by using the newton's law, F=mass x A, we have
T1= (24 + 90 )x 13.4= 1527.6 N, where T1 is the <span>Tension in upper rope
</span> and
T2= ( 90 )x 13.4= 1206N, where T2 is the Tension in lower rope
When the elevator accelerates downward at a rate of 3.6 m/s², the value of the acceleration becomes
A=9.8 - 3.6 = 6.2 m/s²
T1= (24 + 90 )x 6.2= 706.8 N, where T1 is the Tension in upper rope
and
T2= ( 90 )x 6.2= 558N, where T2 is the Tension in lower rope
Car, computer,drill,air plane,television, vending machine
