The SI unit of energy is the Joule .
Any kind of energy ... electrical, mechanical, nuclear, solar,
wind etc. It's easy to change from one form to another ... we
do it every day ... and they all have the same unit.
Answer:
I do agree with the student. Because imagene you have a tissue and a stick. And you throw them at the same speed , the stick will go farther because it' s heavier but the tissue would just blow around and not go forward because it is not heavy enought.
Explanation:
Hope this is correct have a terrific day.
Given that,
Puck slide total Deltax = 12m
Puck and board Mk = 0.10
Find the initial speed = ?
We know that,
Vf^2-Vi^2 = 2a Deltax
-Vi^2 = -2MkgDeltax ............(1)
then,
fk = -Mk mg = ma
a = -Mkg .........(2)
From equation (1),
Vi^2 = 2MkgDeltax
Vi = âš2MkgDeltax [g=9.8m/s^2]
Vi = âš2(0.10)(0.98)(12)
Vi = âš0.2(9.8)(12)
Vi = âš1.92(12)
Vi = âš23.52
Vi = 4.8 m/s
Therefore the initial speed of the puck Vi = 4.8 m/s
Answer:
19.5°
Explanation:
The energy of the mass must be conserved. The energy is given by:
1) 
where m is the mass, v is the velocity and h is the hight of the mass.
Let the height at the lowest point of the be h=0, the energy of the mass will be:
2) 
The energy when the mass comes to a stop will be:
3) 
Setting equations 2 and 3 equal and solving for height h will give:
4) 
The angle ∅ of the string with the vertical with the mass at the highest point will be given by:
5) 
where l is the lenght of the string.
Combining equations 4 and 5 and solving for ∅:
6) 
Answer:
The change in entropy ΔS = 0.0011 kJ/(kg·K)
Explanation:
The given information are;
The mass of water at 20.0°C = 1.0 kg
The mass of water at 80.0°C = 2.0 kg
The heat content per kg of each of the mass of water is given as follows;
The heat content of the mass of water at 20.0°C = h₁ = 83.92 KJ/kg
The heat content of the mass of water at 80.0°C = h₂ = 334.949 KJ/kg
Therefore, the total heat of the the two bodies = 83.92 + 2*334.949 = 753.818 kJ/kg
The heat energy of the mixture =
1 × 4200 × (T - 20) = 2 × 4200 × (80 - T)
∴ T = 60°C
The heat content, of the water at 60° = 251.154 kJ/kg
Therefore, the heat content of water in the 3 kg of the mixture = 3 × 251.154 = 753.462
The change in entropy ΔS = ΔH/T = (753.818 - 753.462)/(60 + 273.15) = 0.0011 kJ/(kg·K).
