Sound cannot travel through:
a) air
b) iron
c) water
d)vacuum
2.
In which of the following material is the speed of sound maximum?
a) iron
b) sea water
c) fresh water
d)air
3.
The frictional force exerted by fluids is called:
a) drag
b) sliding friction
c) rolling friction
d)none of these
4.
A flying machine offering the least frictional force should be:
a) regular
b) tree-like
c) a symmetrical with many arms
d) streamlined
5.
Friction between two flat surfaces cannot be reduced by:
a) greasing
b) polishing
c) using ball bearing
d) decreasing the area.
6.
A musical instrument which produces sound by blowing air into it:
a) sitar
b) guitar
c) flute
d) tabla.
7.
The maximum displacement of an object about its mean position is called:
a) amplitude
b) frequency
c) time period
d) vibration.
8.
Lubrication of the moving surfaces:
a) reduces friction
b) removes friction
c) increases friction
d) has no effect
on friction
Answers
Answer:
1:- sound can't travel in vaccum because it needs air to travell
2:- (c) option is correct
3:- (a) option is correct
4:- (c) option is correct
5:- (a) option is correct
6:- (c) option is correct
7:- (b) option is correct
8:- (a) option is correct
Answer:
please mark my Brainliest solve answer reading
Answer-1 Sound waves are travelling vibrations of particles in media such as air, water or metal. So it stands to reason that they cannot travel through empty space, where there are no atoms or molecules to vibrate.
Answer-2 Speed of sound in solid is maximum. Hydrogen and glycerine are gas and liquid respectively. Among lead and iron, speed of sound is maximum in iron. Answer-3 Drag is the resistance force or friction force in fluid. ... The dynamic friction is the friction that must be overcome to maintain steady motion of one object relative to another because they remain in contact. Answer-4 A flying machine offering least frictional force , should be Irregular tree like Symmetrical with many arms Streamlined. Answer-5 Friction can be minimized by using lubricants like oil and grease and by using ball bearing between machine parts. A substance that is introduced between two surfaces in contact, to reduce friction, is called a lubricant. Answer-6 Woodwind instruments
Woodwind instruments produce sound when the player blows air against a sharp edge or through a thin piece of wood called reed, causing a column of air to vibrate. The instrument itself does not vibrate. Answer-7 Amplitude
Amplitude, in physics, the maximum displacement or distance moved by a point on a vibrating body or wave measured from its equilibrium position. ... It is equal to one-half the length of the vibration path. Answer-8 Lubrication is the control of friction and wear by the introduction of a friction-reducing film between moving surfaces in contact. The lubricant used can be a fluid, solid, or plastic substance. ... Many different substances can be used to lubricate a surface. Oil and grease are the most common.