Answer:
False
Explanation:
According to the big bang theory, matter was an infinitely small and very high density point which at one point exploded and expanded in all directions, creating what we know as our Universe, which also includes space and time . This happened about 13.8 billion years ago. Theoretical physicists have managed to reconstruct this chronology of events from 1/100 of a second after the Big Bang. After the explosion, while the Universe expanded, it cooled sufficiently and the first subatomic particles were formed: Electrons, Positrons, Mesons, Barions, Neutrinos, Photons among others. Today more than 90 particles are known. This theory solves many unknowns and is very well received by the scientific community, however there is still much to solve, for example, one of the great unsolved scientific problems in the expanding Universe model is whether the Universe is open or closed.
An attempt to solve this problem is to determine if the average density of matter in the Universe is greater than the critical value in Friedmann's model. The mass of a galaxy can be measured by observing the movement of its stars; multiplying the mass of each galaxy by the number of galaxies, it is seen that the density is only 5 to 10% of the critical value.
The change of color. Each color has a different wavelength therefore a different frequency.
For those seeking for the answer, its a source of electrical energy.
Answer:
1. 0.45 s.
2. 4.41 m/s
Explanation:
From the question given above, the following data were obtained:
Height (h) = 1 m
Time (t) =?
Velocity (v) =?
1. Determination of the time taken for the pencil to hit the floor.
Height (h) = 1 m
Acceleration due to gravity (g) = 9.8 m/s²
Time (t) =?
h = ½gt²
1 = ½ × 9.8 × t²
1 = 4.9 × t²
Divide both side by 4.8
t² = 1/4.9
Take the square root of both side
t = √(1/4.9)
t = 0.45 s.
Thus, it will take 0.45 s for the pencil to hit the floor.
2. Determination of the velocity with which the pencil hit the floor.
Initial velocity (u) = 0 m/s
Acceleration due to gravity (g) = 9.8 m/s²
Time (t) = 0.45 s.
Final velocity (v) =?
v = u + gt
v = 0 + (9.8 × 0.45)
v = 0 + 4.41
v = 4.41 m/s
Thus, the pencil hit the floor with a velocity of 4.41 m/s
Answer:
(a) The announcer's claim is incorrect because the divers enter at a speed of 20.4 and not 25 m/s as announced
(b) it’s possible for a diver to enter the water with the velocity of 25 m/s if he has initial velocity of 14.4 m/s. The upward initial velocity can’t be physically attained
Explanation:
(a)
To find the final velocity 
for an object traveling distance h taking the initial vertical component of velocity as 
the kinematics equation is written as
where a is acceleration
Substituting g for a where g is gravitational force value taken as 9.81
Since the initial velocity is zero, we can solve for final velocity by substituting figures, note that 70 ft is 21.3 m for h
= 20.44275
Therefore, the divers enter with a speed of 20.4 m/s
The announcer's claim is incorrect because the divers enter at a speed of 20.4 and not 25 m/s as announced
(b)
The divers can enter water with a velocity of 25 m/s only if they have some initial velocity. Using the kinematic equation
Since we have final velocity of 25 m/s
= 14.390761 m/s
Therefore, it’s possible for a diver to enter the water with the velocity of 25 m/5 if he has initial velocity of 14.4 m/s
In conclusion, the upward initial velocity can’t be physically attained
