Answer:
a) 1.2*10^-7 m
b) 1.0*10^-7 m
c) 9.7*10^-8 m
d) ultraviolet region
Explanation:
To find the different wavelengths you use the following formula:

RH: Rydberg constant = 1.097 x 10^7 m^−1.
(a) n=2

(b)

(c)

(d) The three lines belong to the ultraviolet region.
<em>projectile can only follow the straight line path when it is launched upward straightly so the correct option is <u>90 degree with respect to horizontal x -axis ..:)</u></em>
okay this is kinda easy
<u>What is the gravitational field strength on the moon?</u>
The Moon has a gravitational field strength of 1.6 N/kg.
Answer:
Explanation:
Let T be the tension in the swing
At top point 
where v=velocity needed to complete circular path
r=distance between point of rotation to the ball center=L+\frac{d}{2} (d=diameter of ball)
Th-resold velocity is given by 
To get the velocity at bottom conserve energy at Top and bottom
At top 
Energy at Bottom 
Comparing two as energy is conserved



