Answer:
Let the weight of the ruler be X.
Now X acts in the middle, so we have 55-50 = 50cm
Since left hand movement= right hand movement
X(55-50)=90(95-55)
5X= 90×40
X=320cm
Hence the weight of the ruler is 320g
Explanation:
Answer:
The angular separation between the red and violet components of the spectrum that emerges from the glass is 1.72°
Explanation:
Given:
Refractive index for red light 
Refractive index for violet 
Refractive index for air 
Incident angle 
28.30°
According to the snell's law,
For red light,
Where 
transmitted angle for red light
50.18°
For violet light,
Where 
transmitted angle for violet light
51.9°
Angular separation between red and violet light is given by,
1.72°
Therefore, the angular separation between the red and violet components of the spectrum that emerges from the glass is 1.72°
There are two torques t1 and t2 on the beam due to the weights, one torque t3 due to the weight of the beam, and one torque t4 due to the string.
You need to figure out t4 to know the tension in the string.
Since the whole thing is not moving t1 + t2 + t3 = t4.
torque t = r * F * sinФ = distance from axis of rotation * force * sin (∡ between r and F)
t1 =3.2 * 44g
t2 = 7 * 49g
t3 = 3.5 * 24g
t4 = t1 + t2 + t3 = 5570,118
The t4 also is given by:
t4 = r * T * sin Ф
r = 7
Ф = 32°
T: tension in the string
T = t4 / (r * sinФ)
T = t4 / (7 * sin(32°))
T = 1501,6 N
The Doppler effect says that the observed wavelength is shortened
when the source is approaching the observer, and lengthened when
the source is receding from the observer.
All we can say about the police car and its siren is that the sound/color
has a shorter wavelength as it approaches us, and a longer wavelength
as it recedes.
Any of these pairs of answers would say that:
A -- A
C -- A
D -- A
or
D -- D
For each of these pairs, the second wavelength is longer than the first one.
(We don't know which pair is the actual one, because we don't know the actual color of the police car.)
