Answer: 232 nm
Explanation: As it is well known the energy for the one dimentional box is given by:

where h is the Planck constant, m the electron mass and L the width of the box. n is the energy level
For n=3 we a energy equal :9.62 * 10^-19 J= 6.01 eV
For n=1 the energy is: 1.069 *10^-19 J=0.66 eV
The energy difference Is 5.35 eV so by using this relationship
λ=1240/Energy = 232 nm
Answer: 31.85 m/s
Explanation:
Since we are talking about constant acceleration, we can use the following equation to find the speed
of the rocket:

Where:
is the distance the rocket has traveled
is the time in which the rocket has traveled the distance 
Solving the equation with the given data:

This is the rocket's speed
Answer:
a) Acceleration is zero
, c) Speed is cero
Explanation:
a) the equation that governs the simple harmonic motion is
x = A cos (wt +φφ)
Where A is the amplitude of the movement, w is the angular velocity and φ the initial phase determined by the initial condition
Body acceleration is
a = d²x / dt²
Let's look for the derivatives
dx / dt = - A w sin (wt + φ)
a = d²x / dt² = - A w² cos (wt + φ)
In the instant when it is not stretched x = 0
As the spring is released at maximum elongation, φ = 0
0 = A cos wt
Cos wt = 0 wt = π / 2
Acceleration is valid for this angle
a = -A w² cos π/2 = 0
Acceleration is zero
b)
c) When the spring is compressed x = A
Speed is
v = dx / dt
v = - A w sin wt
We look for time
A = A cos wt
cos wt = 1 wt = 0, π
For this time the speedy vouchers
v = -A w sin 0 = 0
Speed is cero
The transfer is perpendicular
Surprised
I knew this<span />
A^2 + b^2=c^2
that is how to find magnitude
xcos0=20cos180
ycos0=20sin270
that should give you the vectors
and your answer should state the quadrant degree which it is in and vector and direction it is in like west,south