Answer:
a
e(k) = \frac{2a}{c} * sin (\frac{k*a}{2} )
b
G_{v} = \frac{d e(k ) }{dk } = \frac{a^2}{c} * cos (\frac{k* a}{2} )
Explanation:
From the question we are told that
The velocity of transverse waves in a crystal of atomic separation is
Generally the dispersion relation is mathematically represented as
=>
=>
=>
Generally the group velocity is mathematically represented as
Answer:
3.True. The magnitude of momentum is the same
Explanation:
Let's propose the solution of the problem
The initial moment is
p₀ = m v
The final moment
= m (-v)
p₀ = -
Now we can review the claims
1. False. We see that the moment module is the same, but its direction changes
2. False. The impulse is a vector
3.True. The magnitude of momentum is the same
Answer:
Approximately .
Explanation:
The change in the gravitational potential energy of the pendulum is directly related to the change in its height.
Refer to the sketch attached. The pendulum is initially at . Its highest point is at
. The length of segment
gives the change in its height.
The lengths of and
are simply the length of the string,
. To find the length of
, start by calculating the length of
.
forms a leg in the right triangle
. Besides, it is adjacent to the
angle
. Its length would be:
.
The length of would thus be
.
The change in gravitational potential energy can be found with the equation
. In this equation,
In this case, and
. Therefore:
.