Answer:
3 a is the ans i think so ....
Explanation:
Given that,
Mass of the cart, 
Mass of the cart 2,
Final speed of cart 2, 
Final speed of cart 1 is 0 as it comes to rest.
Let us assume that the initial velocity of the cart 2 is 0. So using the conservation of linear momentum as :

So, the initial velocity of the 1.0-kg cart is 0.9 m/s.
at t=T/6, total distance covered= 2*pi*r/6 and displacement= r
difference of them = 2*t
so, 2*pi*r/6- r =2(1/6)=1/3
r=1/(pi-3)=7.062
Answer:
a) 
b) 
Explanation:
The energy of the photon (E) for
orbit of the hydrogen atom is given as:

where,
= 13.6 eV
n = orbit
a) Now for the transition from n = 4 to n = 5


b) Now for the transition from n = 5 to n = 6

