Explanation:
The lines in the spectra of star is due to absorption of light emitted by star by different elements present in atmosphere of the star .
If some element is present in the outer atmosphere of he star , it will absorb a particular portion of light , for which there will be black line in the spectrum .
These are called Fraunhoffer's lines .
Now there is no such line at the place of Helium in the light spectrum . This means that Helium element is not present in the outer atmosphere of the star.
Answer:
Explanation:
Given,
Width of slit, W = 5.7 x 10⁻⁴ m
Distance between central bright fringe, L = 4 m
distance between central bright fringe and first dark fringe, y = 4 mm
Diffraction angle
Now.
m = 1
Ans: a = 2.50 m/s^2
Explanation:
First convert the mass in its standard unit i.e. kilogram(kg):
2250 lbs = 1020.583kg
Next use Newton's Second law:
F = ma
Where F = 2552N
m = 1020.583kg
=> a = (2552/1020.583)
a = 2.50 m/s^2
Answer is B- 200 m
Given:
m (mass of the car) = 2000 Kg
F = -2000 N
u(initial velocity)= 20 m/s.
v(final velocity)= 0.
Now we know that
<u>F= ma</u>
Where F is the force exerted on the object
m is the mass of the object
a is the acceleration of the object
Substituting the given values
-2000 = 2000 × a
a = -1 m/s∧2
Consider the equation
<u>v=u +at</u>
where v is the initial velocity
u is the initial velocity
a is the acceleration
t is the time
0= 20 -t
t=20 secs
s = ut +1/2(at∧2)
where s is the displacement of the object
u is the initial velocity
t is the time
v is the final velocity
a is the acceleration
s= 20 ×20 +(-1×20×20)/2
<u>s= 200 m</u>
Answer:
copying another writer's work with no attempt to acknowledge that the material was found in external source is considered as a direct plagiarism.
