A girl weighing 50 kg is standing on a pencil heels , each having a cross - section of 1cm to the power of 2 . An elephant weighing 200 kg and foot area of cross - section of 250 cm to the power of 2 standing on the floor . Which of the two exerts more pressure on the floor ?(given acceleration due to gravity = 10 m/s to the power of 2)
I also have a doubt wether this answer is also correct as per my teacher :
1 . girl's weight = 50 x 10 m/s to the power of 2 = 500 N
cross - section of each feet = (the question is that each has a cross section of 1 cm to the power of 2. A girl can stand only on 2 feets . So it
becomes 2cm to the power of 2 as it is two legs)
= 2 cm to the power of 2 = 0.0002 m to the power of 2 )
pressure = 500 / .0.0002 = 2500000 pa
2 . elephant's weight = 200 x 10 m/s to the power of 2 = 2000 N
cross - section ( as elephant stands on 4 feets) = 250 cm to the power of 2 x 4 = 1000 cm to the power of 2 = 0.1 m to the power of 2
pressure = 2000 / 0.1 = 20000 pa
