let the distance of pillar is "r" from one end of the slab
So here net torque must be balance with respect to pillar to be in balanced state
So here we will have

here we know that
mg = 19600 N
Mg = 400,000 N
L = 20 m
from above equation we have



so pillar is at distance 10.098 m from one end of the slab
Answer: when a object gets slowed down, it's force is either going into friction and drag, if it's on the ground, and weight+drag+friction, if it's in the air.
Explanation:
No. Oxygen( an atmosphere to contain the oxygen),water ,sunlight(energy)
Here we know that mass of the person is 90 kg
His weight is given as 30 lbf
so here we can convert it into Newton as we know that
1 lbf = 4.45 N
Now from above conversion

now we can use this to find the gravity at this height



now we know that with height gravity varies as



so above is the height from the surface of earth