Answer:
A) The wave equation is given as

According to the above equation, k = 0.004 and ω = 5.05.
Using the following identities, we can find the period of the wave.

T = 1.25 s.
For the horizontal distance travelled by one period of time, x = λ.


B) The wave number, k = 0.004 . The number of waves per second is the frequency, so f = 0.8.
C) The propagation speed of the wave is
The velocity of the wave is the derivative of the position function.

The maximum velocity is when the derivative of the velocity function is equal to zero.

In order this to be zero, cosine term must be equal to zero.

The reason that cosine term is set to be 5π/2 is that time cannot be zero. For π/2 and 3π/2, t<0.

Answer:
The speed is 
Explanation:
From the question we are told that
The angle of slant is 
The weight of the toolbox is 
The mass of the toolbox is 
The start point is
from lower edge of roof
The kinetic frictional force is 
Generally the net work done on this tool box can be mathematically represented as

The workdone due to weigh is = 
The workdone due to friction is = 
Substituting this into the equation for net workdone

Substituting values


According to work energy theorem


From the question we are told that it started from rest so u = 0 m/s

Making v the subject
Substituting value


Answer:
d
Explanation:
it has high pressure of speed
Answer:
<u>Very low</u>
<u>Explanation:</u>
It is fair to say to a reasonable extent that there are very low chances that radio transmissions from Earth or messages sent on distant space probes will ever be received by living beings
.
Bear in mind that for years some scientists have believed without any substantial evidence that there are other living beings in distant space.
Gravitational I think would be the answer, Hope this helps!