How much heat energy (in megajoules) is needed to convert 7 kilograms of ice at –9°c to water at 0°c? a. 2.13 mj b. 2.48 mj c. 3.09 mj d. 3.26 mj

2471 kJ

Explanation:

The problem can be split into two steps:

1- Calculate the heat energy needed to raise the temperature of the ice from -9 C to 0 C

2- Calculate the heat energy required to melt the ice

Let's solve them separately.

1- The heat energy needed to raise the temperature of the ice from -9 C to 0 C is given by:

where

m=7 kg is the mass of the ice

Cs=2108 J/kgK is the specific heat capacity of ice

is the temperature gain

Substituting into the formula,

2- the heat energy required to melt the ice is given by

where

m=7 kg is the mass of the ice

is the specific latent heat of fusion for ice

Substituting into the formula,

3- So, the total heat energy needed for the entire process is

statement #3 on andre"s list is false.

we have been given a quadratic function and we need to restrict the domain such that it becomes a one to one function.

we know that vertex of this quadratic function occurs at (5,2).

further, we know that range of this function is .

if we restrict the domain of this function to either or , it will become one to one function.

let us know find its inverse.

upon interchanging x and y, we get:

let us now solve this function for y.

hence, the inverse function would be if we restrict the domain of original function to and the inverse function would be if we restrict the domain to .