Answer:
Total energy is 170 kJ
Explanation:
Given data:
latent heat of fusion of alcohol is 25 kcal/kg
melting point of alcohol is -114 degree c
specific heat us 0.60 k cal/kg degree c
energy need for 2 kg solid alcohol is
for Melting:
Energy Q is calculated as
Energy, Q = 25 \times 2.0 kg = 50 kJ
Energy required for Heating liquid:
Energy, ΔH = 2.0 kg \times 0.60 \times (100°C) = 120 kJ
Total energy = (50 kJ + 120 kJ) = 170 kJ
The acceleration is 
Explanation:
We can solve the problem by applying Newton's second law of motion: in fact, the net force acting on an object is equal to the product between the mass of the object and its acceleration. Therefore we can write:

where:
is the resultant force acting on the object
m is its mass
a is its acceleration
In this problem, we have the following forces acting on the system:
(forward)
(backward)
So, Newton's second law can be rewritten as:

where:
m = 1050 kg is the mass of all the students
Solving the formula for a, we find the acceleration of the system:

Learn more about Newton's second law:
brainly.com/question/3820012
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Answer: Atmosphere and geosphere.
Geo-sphere is the solid part of the earth. Hydrosphere is the water part. The living things on the earth make up the biosphere. The gases, water vapors etc make up the atmosphere. When a volcanic eruption adds carbon dioxide to the air, the carbon-dioxide is being added from geosphere to the atmosphere. Hence, there is interaction between atmosphere and geosphere.
Here,
m=80 kg
R= 6.4*10^6 m
and t=24*3600=86400 s
Centripetal acceleration:
a=ω²r
=(2

/86400)^2 * 6.4*10^6
=0.034 m/s²
I’m not sure about the first one, but I know that in order for a substance to be in a plasma stage it must be hot, so I would say C) for the second question :)