Answer:
Cosmic ray's frame of reference: 99,875 years
Stationary frame of reference: 501,891 years
Explanation:
First of all, we convert the distance from parsec into metres:

The speed of the cosmic ray is

where
is the speed of light. Substituting,

And so, the time taken to complete the journey in the cosmic's ray frame of reference (called proper time) is:

Converting into years,

Instead, the time elapsed in the stationary frame of reference is given by Lorentz transformation:

And substituting v = 0.98c, we find:

Those organic structures that do not seem to play any important biological function in the organism that possesses them are known as vestigial structures.
<h2>What is a vestigial structure?</h2>
A vestigial structure is one that has atrophied or lost its original function throughout the course of evolution.
- It generally refers to those organic structures that were useful at some point, but are now practically or totally useless.
- These structures are preserved as an inheritance of the evolutionary process, because at some point an ancestor of the current species had that structure, which was functional, but it ceased to be important and would end up atrophy.
Therefore, we can conclude that vestigial structures are structures that some organisms still conserve as an inheritance from their ancestors but that, for some reason or another, are no longer useful for the functioning of the same.
Learn more about vestigial structures here: brainly.com/question/2141655
Answer:
force for start moving is 7.49 N
force for moving constant velocity 2.25 N
Explanation:
given data
mass = 7.65 kg
kinetic coefficient of friction = 0.030
static coefficient of friction = 0.10
solution
we get here first weight of block of ice that is
weight of block of ice = mass × g
weight of block of ice = 7.65 × 9.8 = 74.97 N
so here Ff = Fa
so for force for start moving is
Fa = weight × static coefficient of friction
Fa = 74.97 × 0.10
Fa = 7.49 N
and
force for moving constant velocity is
Fa = weight × kinetic coefficient of friction
Fa = 74.97 × 0.030
Fa = 2.25 N