<span>This is because Helium
has two valence electrons compared to Hydrogen which has only one. Helium has
more energy levels for an electron to jump thus more spectral lines to occur.
The spectral lines relating to each change of energy level would be more
grouped together and hence the greater chance of them falling in the visible
range.</span>
Answer:
The current lags the potential difference by π/2 in an inductor
Explanation:
The potential difference leads to the current by
. Alternate signals such as current and voltage -in this case- are periodic, this means that this signals are repeated at fixed spaces of time. Thus, In an inductor the current lags the potential difference by
.
Answer:
The x-component of
is 56.148 newtons.
Explanation:
From 1st and 2nd Newton's Law we know that a system is at rest when net acceleration is zero. Then, the vectorial sum of the three forces must be equal to zero. That is:
(1)
Where:
,
,
- External forces exerted on the ring, measured in newtons.
- Vector zero, measured in newtons.
If we know that
,
,
and
, then we construct the following system of linear equations:
(2)
(3)
The solution of this system is:
, 
The x-component of
is 56.148 newtons.