Question
Let the speed of sound in air, water and iron by V a
, V w and V i respectively. Which is the correct order of velocity of sound in these media?Solution
The distances between molecules in solids are very small, i.e., solids are more dense - as compared to liquids and gases. Because they are so close, than can collide very quickly, i.e. it takes less time for a molecule of the solid to 'bump' into its neighborhood. Solids are packed together tighter than liquids and gases, hence sound travels fastest in solids. The distances in liquids are shorter than in gases, but longer than in solids. Liquids are more dense than gases, but less dense than solids, so sound travels 2nd fast in liquids. Gases are the slowest because they are the least dense: the molecules in gases are very far apart, compared with solids and liquids. Sound travels faster in liquid than air and fastest in solids. Thus Vi>Vw>Va
Sum of ages of 60 students is 900 years such that the average age of 25 of them is 10 years and average age of another 25 of them is 14 years. Find the ...
The average of the first 7 non-zero multiples of 18 is:
The mean weight of 'w' students in a classroom is 42 kg. When the class teacher, weighing 61.5 kg, is added to the group, the average weight increases b...
- A student calculates the average of five two-digit numbers. If one of them is reversed and the new average increases by 9, and all the numbers are consecut...
If the average of s number is r⁴ and the average r number is s⁴, then find the average of all r+ s numbers
The average weight of 20 boys is 48 kg. However, the weights of three boys, originally 46 kg, 44 kg, and 38 kg, were incorrectly ...
The average of six numbers is 66. When two more numbers are included, the average increases by 2. Find the average of the numbers included.
- The average speed of a car over the first 4 hours is 50 km/h. If the car needs to maintain an average speed of 60 km/h over a total of 8 hours, what should...
There are three distinct numbers ‘u’, ‘v’ and ‘w’. If, u = 240, (u + v) = 540 and (w – v) = 60, then find the average of u, v and w.
...The average score of 28 players in a team is 73. After two new players with scores (x + 8) and (x - 6) joined, the average score decreased by 2 points. ...