Answer: is option C: <em>Prolonged periods of cooling and warming</em>.
Explanation:
In the history of Earth, climate varies time to time. At times, the Earth's atmosphere was much hotter and humid as compare to the present time, but similarly it has been noticed that climate also has been much colder than he present time, whereas the number of glaciers covers much of the Earth's surface. There are two kinds of periods in which we further classified Earth's climate namely, Glacial period, and Inter-glacial periods. It has been noticed that the average global temperature of Earth during glacial periods was around 5.5°C or 10°F, which is less than Earth's present climate. On the other hand, during inter-glacial periods Earth's temperature was about 1.1°C or 2.0°F, which is again higher as compared to current temperature. Over the past 900,000 years, Earth's temperature varied less than 5°C. Scientist believe by looking at the Earth's climate history, that glaciers will proceed again in formation, but it will take thousands of years.
Answer:
a)Work done by fireman= 2.15 Btu
b) Time t= 0.86 sec
Explanation:
Given that
Weight = 280 lbf
We know that 1 lbf = 4.44 N
so 280 lbf = 1245.5 N
Weight =1245.5 N
Height h = 60 ft
We know that
1 ft = 0.3048 m
So 60 ft = 18.28 m
h =18.28 m
Power = 3.5 hp
We know that
1 hp =0.74 KW
So 3.5 hp = 2.61 KW
Power = 2.61 KJ/s
So the work done by fireman = Weight x h
Now by putting the values
Work done by fireman= 1245.5 x 18.28 J
Work done by fireman= 2267.74 J
Work done by fireman= 2.26774 KJ
We know that 1 Btu= 1.05 KJ
So 2.266 KJ = 2.15 Btu
Work done by fireman= 2.15 Btu
We know that ,rate of work is called power.
Power x time = work
2.61 x t = 2.26
So t= 0.86 sec
The correct definition of a fracture is break in the bone
<u>Explanation:</u>
When nay injury results in the breaking or causing any cracking in the bones of any parts then this will lead to fracture. When the injury caused is near the ligament or tissue in which the bone is connected or attached then it will lead to an avulsion fractures. Thus this will lead to the pulling of bone form the original position thereby leading more pain in the spot associated with the fracture.
Sports people are the victims of this type of fracture. Fracture may occur anywhere mostly legs,hands,ankle,hip and elbow. sometimes it may be in finger, shoulder,knee,etc. The main symptoms that are associated with fracture includes, selling, inability in moving the fractured part or pain associated when trying to move that part, Loss of the affected part's function,etc.
To bring something to a stop the same force that was applied to speed it up can be used to stop it. If a greater force is used it will stop quicker.
Answer:
density of the ball is 3.33 g/cc
Explanation:
As we know that the density is the ratio of mass and volume
here we know that
mass = 20 g
volume = 6 cubic cm
so we will have
