Answer:
2274 J/kg ∙ K
Explanation:
The complete statement of the question is :
A lab assistant drops a 400.0-g piece of metal at 100.0°C into a 100.0-g aluminum cup containing 500.0 g of water at 15 °C. In a few minutes, she measures the final temperature of the system to be 40.0°C. What is the specific heat of the 400.0-g piece of metal, assuming that no significant heat is exchanged with the surroundings? The specific heat of this aluminum is 900.0 J/kg ∙ K and that of water is 4186 J/kg ∙ K.
= mass of metal = 400 g
= specific heat of metal = ?
= initial temperature of metal = 100 °C
= mass of aluminum cup = 100 g
= specific heat of aluminum cup = 900.0 J/kg ∙ K
= initial temperature of aluminum cup = 15 °C
= mass of water = 500 g
= specific heat of water = 4186 J/kg ∙ K
= initial temperature of water = 15 °C
= Final equilibrium temperature = 40 °C
Using conservation of energy
heat lost by metal = heat gained by aluminum cup + heat gained by water

Actually moving and not. It is the sum of potential and kinetic energy.
These are two questions and two answers.
Part 1. Fin the value of the ration of velocity C to velocity D.
Answer: 2
Explanation:
1) Formula: momentum = mass * velocity
2) momentum C = mass C * velocity C
3) momentum D = mass D * velocity D.
4) C and D have the same momentum =>
mass C * velocity C = mass D * velocity D
5) mass C = (1/2) mass D => mass C / mass C = 1/2
6) use in the equation stated in the point 4)
velocit C / velocity D = mass D / mass C
using the equation stated in point 5:
mass D / mass C = 1 / [ mass C / mass D] = 1 / [1/2] = 2
=>
7) velocity C / velocity D = mass D / mass C = 2
Part 2: <span>ratio of kinetic energy C to kinetic energy D.
</span>
Answer: 2
Explanation:
1) formula: kinetic energy KE = (1/2) mass * (velocity)^2
2) KE C = (1/2) mass C * (velocity C)^2
3) KE D = (1/2) mass D * (velocity D)^2
4) KE C / KE D =
(1/2) mass C * (velocity C)^2 mass C (velocity C)^2
--------------------------------------- = --------------- * ---------------------- = (1/2) * (2)^2
(1/2) mass D *( velocity D)^2 mass D v(velocity D)^2
= 4 / 2 = 2
Answer: They have different rigidities.
Explanation:
It's an electric motor that converts electric energy into Mechanical energy