An automobile engine provides 631 Joules of work to push the pistons. In this process the internal energy changes by -2881 Joules. Calculate q for the engine. This represents the amount of heat that must be carried away by the cooling system.

q = - 2250 Joules

Explanation:

work, w = 631 joules

internal energy ΔU = -2881 joules

q = ?

The relationship between work, internal energy and q is given by the equation;

q + w =  ΔU

Since work is done by the automobile energy, it would have a negative sign, hence;

ΔU = q - w

Inserting the values and solving for q;

ΔU + w = q

q =  -2881 + 631

q = - 2250 Joules

b is the correct

the mantle

explanation:

earth is divided into three layers: the crust or the outermost layer on which we live; the underlying, middle layer - the mantle - and the core (the innermost layer of earth).