The speed of sound is greater in ice (4000 m/s), then in water (1500 m/s), then in air (340 m/s). The explanation for this is the differente state of the matter in the three cases.
In fact, sound waves travel faster in solids (like ice), then in liquids (like water), then in gases (like air). This is because the speed of the sound wave depends on the density of the medium: the greater the density, the faster the sound wave. This can be easily understood by thinking at how a sound wave propagates: a sound wave is a vibration of molecules, which is transmitted throughout the medium by collision of the molecules. Therefore, the smaller the spacing between the molecules (such as in solids), the more efficient is the propagation, and so the sound wave is faster. On the contrary, there is a large spacing between molecules in gases (such as in the air), so there are less collisions between the molecules and so the wave is not transmitted efficiently, and so it has less velocity.
Answer:
0.09 N
Explanation:
We are given that
Radius of disk,r=6 cm=
1 m=100 cm
B=1 T
Current,I=3 A
We have to find the frictional force at the rim between the stationary electrical contact and the rotating rim.
Torque due to friction
Where friction force=F
Substitute the values
SONAR stands for "sound navigation and ranging,” and it is used to map and explore the ocean floor.
"Electrostatic forces are attractive or repulsive forces between particles that are caused by their electric charges."
Answer:
It's the duration between successive new moons. Also called a lunation or synodic month, it has a mean period of 29.53059 days (29 days 12 hours and 44 minutes).
