The statement ‘Big bang theorists
believe that the universe is expanding and will eventually contract’ is false. The
answer is letter B. The big bang theory suggests that the origin of the
universe began with that exploded and expanded. It also states that the
universe began in a single form of high condensed reactive matter and exploded
forming the galaxies, planets, stars and other celestial bodies.
Answer:
Power = 2.45Kw or 2450 Watts.
Explanation:
<u>Given the following data;</u>
Mass, m = 250kg
Height, h = 2m
Time, t = 2secs
We know that acceleration due to gravity, g is equal to 9.8m/s²
Power can be defined as the energy required to do work per unit time.
Mathematically, it is given by the formula;
But Energy = mgh
Substituting into the equation, we have

Power = 2450 Watts
To convert to kilowatt (Kw), we would divide by 1000
Power = 2450/1000
Power = 2.45Kw.
Therefore, the average power output of the weightlifter is 2.45 Kilowatts.
Given data:
* The mass of the ball is 2 kg.
* The gravitational field strength at the surface of planet X is 5 N/kg.
Solution:
The weight of the ball on the planet X is,

where m is the mass of ball, a is the gravitational field strength,
Substituting the known values,

Thus, the weight of the ball on the surface of planet X is 10 N.
Answer:
0.08 ft/min
Explanation:
To get the speed at witch the water raising at a given point we need to know the area it needs to fill at that point in the trough (the longitudinal section), which is given by the height at that point.
So we need to get the lenght of the sides for a height of 1 foot. Given the geometry of the trough, one side is the depth <em>d</em> and the other (lets call it <em>l</em>) is given by:

since the difference between the upper and lower base is the increase in the base and we are only at halft the height.
Now we can calculate the longitudinal section <em>A</em> at that point:

And the raising speed <em>v </em>of the water is given by:

where <em>q</em> is the water flow (1 cubic foot per minute).
Let the height where we are trapped is H
now to find the time to reach the key at the bottom is given as

now we have


now if the speed of sound is considered to be 340 m/s then time taken by the sound to reach at the top is given as

now the total time is given as

now by solving above equation we have
H = 48 m
now height of one floor is 3 m
so our position must be
