Answer:
1,373.4 N
Explanation:
The mass of the table acts at the centre in addition to the books since that is the centre of gravity of the table.
Mass of books will be 10kg+20kg+30kg=60 kg
Total mass of table and books will be 500kg+60kg=560 kg
This mass is evenly distributed into the four legs hence 560kg/4 legs=140 kg per leg
Force is product of mass and acceleration due to gravity hence F=gm
Taking g as 9.81 m/s2 then
F=140*9.81=1,373.4 N
Therefore, rhe normal force is equivalent to 1,373.4 N
A variable is a letter so just be like
13a or something like that
Taking specific heat of lead as 0.128 J/gK = c
We have energy of ball at 7.00 meter height = mgh = 
When leads gets heated by a temperature ΔT energy needed = mcΔT
=
ΔT
Comparing both the equations
=
ΔT
ΔT = 0.536 K
Change in temperature same in degree and kelvin scale
So ΔT = 0.536 
if the pointy thingy in your compass is pointing north, that means it's being (pulled toward) something near Earth's north pole