Answer:
D.vibrations that cause changes in air pressure
Explanation:
Sound is a type of wave.
A wave is a periodic disturbance/oscillation that trasmits energy without transmitting matter. There are two different types of waves:
- Transverse waves: in a transverse wave, the direction of the oscillation is perpendicular to the direction of motion of the wave. These waves are characterized by the presence of crests (points of maximum positive displacement) and troughs (points of maximum negative displacement). Examples of transverse wave are electromagnetic waves.
- Longitudinal waves: in a longitudinal wave, the direction of the oscillation is parallel to the direction of motion of the wave. These waves are characterized by the presence of compressions (regions where the density of particle is higher) and rarefactions (regions where the density of particle is lower). Examples of longitudinal waves are sound waves.
Sound waves, in particular, consist of vibrations of the particles in a medium - most commonly, air - that occur back and forth along the direction of motion of the wave. Because of these motion, the air will have areas of higher pressure (which correspond to the compressions), where the density of particles is higher, and areas of lower pressure (which correspond to the rarefactions), where density of particles is lower.
Answer:
Explanation:
For an electric force, F the formula:
F = kQq/r^2
Given:
r2 = 1/2 × r1
F1 × r1 = k
F1 × r1 = F2 × r2
F2 = (F1 × r1^2)/(0.5 × r1)^2
= (F1 × r1^2)/0.25r1^2
= 4 × F1.
Answer:
Temperature : 92.9 F
Internal Energy change: -2.53 Btu/lbm
Explanation:
As
mh1=mh2
h1=h2
In table A-11 through 13E
p2=120Psi, h1= 41.79 Btu/lbm,
u1=41.49
So T1=90.49 F
P2=20Psi
h2=h1= 41.79 Btu/lbm
T2= -2.43F
u2= 38.96 Btu/lbm
T2-T1 = 92.9 F
u2-u1 = -2.53 Btu/lbm
Answer:
B. The maximum angle decreases
Explanation:
If θ be the maximum angle of a slope that allows a crate placed on it to remain at rest , following condition exists .
tanθ = μ , θ is called angle of repose . μ is coefficient of static friction .
So the tan of angle of repose θ is proportional to coefficient of static friction.
If coefficient of static friction is less than .7 , naturally angle of repose will also become less ,ie, it at lower angle of inclination , the object will start slipping .
When work is done and a force is transferred an object must move