Answer:
1.9976 m
Explanation:
An iron bar whose initial length is 2m has its temperature increased from 20 ° C to 120 ° C. What is the final length of the bar? (consider that the coefficient of expansion of iron) is 1.2 x 10-5 1 / ° C (3 points)
Given that,
Initial length of an iron bar, 
The temperature increased from 20°C to 120°C
The coefficient of expansion of iron is 
We need to find the final length of the bar.
The linear expansion equation is given by :
Where 
is the change in length
Also, 
L is final length
So, the final length of the bar is 1.9976 m
Answer:
The correct answer for this Question is B
Explanation:
WIND AND WATER EROSION (B)
Answer:
Explanation:
Before Thomson's discovery, atoms were believed according to the "Dalton's atomic theory" to be the smallest indivisible particle of any matter. This makes atoms the smallest unit of a matter.
Thomson in 1897, used the discharge tube to discover cathode rays which are today called electrons.
The discovery of electrons provided more light into the structure and nature of atoms. Atoms were now being seen in a different light as particles that are made up of other smaller sized particles.
Thomson through his experiment was able determine perfectly well the nature of the rays he saw emanating from the cathode. One of his findings shows that the rays are negatively charged and are repelled by negative charges.
The discovery of electrons further led to more works on the atom and other particles were discovered. Atoms were no longer seen as indivisible or the smallest particles of matter.
Answer:
a) 1.25e15 kg
b) 4.17e20 J
c) 44.55 years
Explanation:
To find the volume you need to multiply 218 km * 25 km * 250 m (be careful with units), so the volume is 1.3625e12 m^3, if you multiply this value by the density you will obtain the mass, that is 1.25e15 kg.
To find the energy needed to melt the ice, you use the latent heat, in this case, it is 3.34e5 J/kg. Now you multiply this value by the mass, so you need 4.17e20 J to melt the iceberg.
The surface area of the iceberg is 545e7 m^2, so the ice absorbs 594e9 W, one W is one J/s, so in 12 hours the iceberg absorbs 2.56e16 J, so in 365 days absorbs 9.36e18 J. Now you just divide 4.17e20 J by the amount f energy per year, and obtain 44.55 years.
