Question

The displacement of an elastic wave is given by the function Y=3 sin wt+4coswt
where y is in cm and tis in second. Calculate the resultant amplitude.
​

Answer 1

Explanation:

y=3sinwt + 4coswt

A1= 3

A2=4

y1= 3sinwt

y2=4coswt= 4sin(wt+is/2

resultant amplitude = √3^2+4^2

= √9+16=5 cm

Answer 2

Explanation:

The gas is kept at 273 K and 1 atm pressure.

So, we can also say that the gas is kept in STP .

Now, we know at STP :

One mole of gas has volume of 22400 \ cm^322400 cm

3

.

We can also say, 6.022\times 10^{23}6.022×10

23

molecules of H_2H

2

have volume equal to 22400 \ cm^322400 cm

3

.

Therefore ,

Total number of molecules in 1\ cm^31 cm

3

is , n=\dfrac{6.022\times 10^{23}}{22400}=2.68\times 10^{19}n=

22400

6.022×10

23

=2.68×10

19

molecules.

Now,

We know H_2H

2

is diatomic gas .

Therefore , degree of freedom of one molecule is 5 [ degree of freedom of diatomic gas is 5 ].

So , degree of freedom of 2.68\times 10^{19}2.68×10

19

molecules is , 2.68\times 10^{19}\times 5=1.34\times 10^{20}.2.68×10

19

×5=1.34×10

20

.

Hence , this is the required solution.