Answer:
The value is 
Explanation:
From the question we are told that
The mass of the ice cube is 
The temperature of the ice cube is
The mass of the copper cube is 
The final temperature of both substance is 
Generally form the law of thermal energy conservation,
The heat lost by the copper cube = heat gained by the ice cube
Generally the heat lost by the copper cube is mathematically represented as
![Q = m_c * c_c * [T_c - T_f ]](https://tex.z-dn.net/?f=Q%20%3D%20%20m_c%20%20%2A%20%20c_c%20%2A%20%20%5BT_c%20%20-%20%20T_f%20%5D)
The specific heat of copper is 
Generally the heat gained by the ice cube is mathematically represented as

Here L is the latent heat of fusion of the ice with value 
So

=>
So
=> 
Answer:
Required energy Q = 231 J
Explanation:
Given:
Specific heat of copper C = 0.385 J/g°C
Mass m = 20 g
ΔT = (50 - 20)°C = 30 °C
Find:
Required energy
Computation:
Q = mCΔT
Q = 20(0.385)(30)
Required energy Q = 231 J
The scale would need 10 aluminum cubes on one side. Figure out how many paper clips would be needed on the other side to balance this. You have to use more than one aluminum cube because you need to have enough cubes so that you get a whole number mass. 10 cubes gives you a total mass of 27 g for the aluminum.
An object's momentum is the product of its mass and its velocity:
p = mv
p is its momentum, m is its mass, and v is its velocity.
Given values:
p = -80kg×m/s
m = 8kg
Plug in these values and solve for v:
-80 = 8v
v = -10m/s
Choice D
As we know that electrostatic force between two charges is given as

here we know that electrostatic repulsion force is balanced by the gravitational force between them
so here force of attraction due to gravitation is given as

here we can assume that both will have equal charge of magnitude "q"
now we have



now we have
