Answer:
(a). 19.0 m/s
(b). 9.5m/s
Explanation:
Assuming speed of sound is 343m/s.
(a).
As the train approaches, from the the Doppler equation we have
solving for we get:
.
And as the train cuts its speed in half, the equation gives
substituting the value of we get:
or 68.6 km per hour, which is the speed of the train before slowing down.
(b).
The speed of the train after slowing down is half the previous speed; therefore,
or 34.3 km per hour.
Answer:
Explanation:
Given that
L = 3 m
M = 2.4 kg
m=0.7 kg
r= L/2 = 1.5 m
The moment of inertia of rod about it center
The moment of inertia of point mass about center of rod
I'= mr² + mr²
So total moment of inertia
By putting the values
Solids - particles are close together in a regular structure and vibrate about fixed positions
liquids - particles are close together but free to move past each other randomly
gases - particles are far apart and move randomly in all directions
The density of a substance changes when it changes state. Its mass does not change. This is because its particles do not disappear - they are just rearranged and occupy a different volume.
Complete Question
The complete question is shown on the first uploaded image
Answer:
The slit width
Explanation:
Assuming the unit on the graph is cm
Given that the slit to screen distance is D = 200 cm = 20 000 m
The wavelength = 633 nm =
slit width a = ?
The width of the spot that is the width of the peak from the graph is
W = 1.6 × 2 = 3.2 cm
Where the 1.6 is the distance from 0 to the right end point of the peak
The change in y i.e has a formula
= Ltanθ
An the width of the spot is 2 ×
W = 2Ltanθ
Applying this formula qsinθ = m
where m = 1 because we a focused on the first zeros ,using small angle approximation we have y
Substituting this into W = 2ltanθ
Using small angle approximation
W = 2ltanθ = 2Lθ
and this is the slit width