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:
Identify the object to be analyzed. For some systems in equilibrium, it may be necessary to consider more than one object. Identify all forces acting on the object. Identify the questions you need to answer. Identify the information given in the problem. In realistic problems, some key information may be implicit in the situation rather than provided explicitly.
Explanation:
Identify the object to be analyzed. For some systems in equilibrium, it may be necessary to consider more than one object. Identify all forces acting on the object. Identify the questions you need to answer. Identify the information given in the problem. In realistic problems, some key information may be implicit in the situation rather than provided explicitly.
Answer: (d)
Explanation:
Given
Mass of object 
Speed of object 
Mass of object at rest 
Suppose after collision, speed is v
conserving momentum

Initial kinetic energy

Final kinetic energy

So, it is clear there is decrease in kinetic energy . Thus, energy decreases and velocity becomes 2 m/s.
Yes,it's true ok? So how have you been doing
Answer:
force (tension) of 29.4 N (upward) in 100 cm
force (tension) of 58.4 N (upward) in 200 cm
Explanation:
Given:
Length of tube = 5 m (500 cm)
Mass of tube = 9
Suspended vertically from 150 cm and 50 cm.
Computation:
Force = Mass × gravity acceleration.
Force = 9.8 x 9
Force = 88.2 N
So,
Upward forces = Downward forces
D1 = 150 - 50 = 100 cm
D2 = 150 + 50 = 200 cm
And F1 = F2
F1 x D1 = F2 x D2
F1 x 100 = F2 x 200
F = 2F
Total force = Upward forces + Downward forces
3F = 88.2
F = 29.4 and 2F = 58.8 N
force (tension) of 29.4 N (upward) in 100 cm
force (tension) of 58.4 N (upward) in 200 cm