When you add up (20N down) and (10N up),
you get a sum of (10N down).
The mass of the object has no effect on the forces.
Now ... I see 5 points for the answer.
Where are the other 25 coming from ?
Silicates that are composed of infinite chains of tetrahedrons are called inosilicates; single chains have a unit composition of SiO 3 or Si 2 O 6, whereas double chains contain a silicon to oxygen ratio of 4:11. Phyllosilicates, or sheet silicates, are formed when three oxygen atoms are shared with adjoining tetrahedrons.
Answer:
Wheelbarrows, fishing rods, shovels, brooms, arms, legs, boat oars, crow bars, and bottle openers are all examples of levers. Levers may be one of the most used simple machine. As with all simple machines like the lever, they are designed to help make work easier to do.
Explanation:
Mass/volume is the formulae
To solve this problem, apply the concepts related to the calculation of the work performed according to the temperature change (in an ideal Carnot cycle), for which you have to:

Where,
C = Heat capacity of the Brick
= Cold Temperature
= Hot Temperature
Integrating,

Our values are given as


Replacing,



Therefore the work perfomed by this ideal carnot engine is 58kJ