1. Frequency: 
The frequency of a light wave is given by:

where
is the speed of light
is the wavelength of the wave
In this problem, we have light with wavelength

Substituting into the equation, we find the frequency:

2. Period: 
The period of a wave is equal to the reciprocal of the frequency:

The frequency of this light wave is
(found in the previous exercise), so the period is:

Answer:
a) t = 19.6 s, b) fr = 1.274 10⁴ N
Explanation:
This is a Newton's second law problem
Y Axis
for the cabin
N₁-W₁ = 0
N₁ = W₁
for the trailer
N₂- W₂ = 0
N₂ = W₂
X axis
for the cabin plus trailer, where friction is only in the cabin
fr = (m₁ + m₂) a
the friction force equation is
fr = μ N
we substitute
μ N₁ = (m₁ + m₂) a
μ m₁ g = (m₁ + m₂) a
a = μ g 
let's calculate
a = 0.65 9.8
a = 1,274 m / s²
a) to find the stopping distance we can use kinematics
Let's slow down the sI system
v₀ = 90 km / h (1000 m / 1km) (1h / 3600s) = 25 m / s
v = v₀ - a t
when it is stopped its speed is zero
0 = v₀ - at
t = v₀ / a
t = 25 / 1.274
t = 19.6 s
b) the friction force is
fr = 0.65 2000 9.8
fr = 1.274 10⁴ N
This is the braking force and also the forces that couple the cars.
Answer:
Hey mate hope its help you....
The final velocity of the Maserati after accelerating at the rate of 85 m/s² for 5 seconds is 431m/s.
<h3>How to calculate the final velocity a moving object?</h3>
From the first equation of equation of motion, final velocity is the sum of the initial velocity and the product of acceleration and time.
It is expressed as;
v = u + at
Where v is final velocity, u is initial velocity, a is acceleration and t is time elapsed.
Given the data in the question;
- Initial velocity u = 6m/s
- Acceleration a = 85m/s²
- Elapsed time t = 5s
- Final velocity v = ?
Plug the given values into the first equation of motion and solve for v.
v = u + at
v = 6m/s + ( 85m/s² × 5s )
v = 6m/s + 425ms/s²
v = 6m/s + 425m/s
v = 431m/s
The final velocity of the Maserati after accelerating at the rate of 85 m/s² for 5 seconds is 431m/s.
Learn more about the first equation of equation here: brainly.com/question/20381052
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