We know,
V= f× wavelength
10.5= f×0.15
f=10.5/0.15
f= 70 Hz
I believe it is noise pollution
Answer:A
Explanation:matter normally occurs in three phases;solid, liquid and gases. They may change from one phase to another due to temperature difference.
The molecules that makes up solids are held together by bonds. When heat is added,the molecules begin to move as a result,the bonds break and it turns to liquid.this process is called melting. The reverse of melting is freezing.
Liquid are made up of molecules that moves more freely than solids. When heat is added to liquid,the molecules gain more energy and begins to move faster. This causes them to turn to gases.
This process is called evaporation. It occurs at different temperature for different substances.
The particles of gases move more faster and are separated by large distances. A gas can change back to a liquid through condensation.
Explanation:
initial height, yo = 2 m
initial velocity, u = 20 m/s
angle of projection,θ = 5 degree
distance of net = 7 m
height of net = 1 m
Let it covers a vertical distance y in time t .
Use Second equation of motion for vertical motion
As it hits the ground in time t, so put y = 0
Taking positive sign, t = 0.84 s
The ball travels a horizontal distance x in time t
X = 20 Cos5 x t
X = 16.76 m
As this distance is more than the distance of net, so it clears the net.
Let t' be the time taken to travel a horizontal distance equal to the distance of net
7 = 20 cos5 x t'
t' = 0.35 s
Let the vertical distance traveled by the ball in time t' is y'.
So,
y' = 2.008 m
So, it clears the net which is 1 m high.
It clears the net by a vertical distance of 2.008 - 1 = 1.008 m and horizontal distance 16.76 - 7 = 9.76 m
your welcome, and have a great day.
Answer:

Explanation:
Average velocity of oxygen molecule at given temperature is

now we have
M = 32 g/mol = 0.032 kg/mol
T = 27 degree C = 300 K
now we have


now for de Broglie wavelength we know that


