Answer: Find the answer in the explanation
Explanation:
Bohr postulated that :
1.) Electrons revolve in specific circular orbits around the nucleus and these orbits can be represented by the letters K, L, M, N.
2.) Electrons revolving in a particular orbit are in a stationary state. They can neither gain energy nor loose energy. 3.) But if an electron jumps from an higher orbit to a lower orbit it will emit energy in the form of radiations. Also if an electron jumps from lower orbit to a higher orbit it excites and absorbs energy in the form of radiations.
4.) Neil Bohr experimental findings about angular momentum of an electron shows more light on the stability of atom and the line spectrum of hydrogen atom
Answer:
(a) 19.62 N
(b) Box moves down the slope
(c) 24.43 N
Explanation:
(a)
2 Kg box causes tension
![T=mgwhere m is mass, g is gravitational force taken as 9.81T=2*9.81 =19.62 N (b) Block mass of 4 Kg [tex]T'-mg sin \theta=0](https://tex.z-dn.net/?f=T%3Dmg%3C%2Fp%3E%3Cp%3Ewhere%20m%20is%20mass%2C%20g%20is%20gravitational%20force%20taken%20as%209.81%3C%2Fp%3E%3Cp%3E%3C%2Fp%3E%3Cp%3ET%3D2%2A9.81%20%3D19.62%20N%20%20%3C%2Fp%3E%3Cp%3E%28b%29%20%20%3C%2Fp%3E%3Cp%3EBlock%20mass%20of%204%20Kg%20%20%3C%2Fp%3E%3Cp%3E%5Btex%5DT%27-mg%20sin%20%5Ctheta%3D0)
hence 
where m is mass and g is gravitational force
T'=4*9.81 sin 35= 22.5071 N
Since T' is greater than 
, then the box moves down the slope
(c)
Acceleration a= 
When moving, the box will exert force T"= 
T"= 4*9.81 sin 35 +(4*0.48)= 24.43 N
Answer:
wavelength = 0.01 m
distance = 162.8 m
Explanation:
Given that;
Speed of sound in water = 1,480 meters per second
Frequency of ultrasound = 125KHZ
From=
v=λf
v= speed of sound
λ= wavelength of sound
f= frequency of sound
λ= 1,480 ms-1/125 * 10^3 Hz
λ= 0.01 m
From
v = 2x/t
where;
v= velocity of sound in water
x= distance traveled
t = time taken
x = vt/2
x = 1,480 ms-1 * 0.220 s/2
x= 162.8 m
