Question

1.Calculate the pressure exerted by a column of water of height 2.5m (density of water, ρw = 1000 kg m–3) and kerosene of same height (density of kerosene, ρk = 800 kg m–3)
2. A man whose mass is 75 kg stands on his feet on a floor. The total area of contact of his two feet with the floor is 0.049 m2 (Take, g = 10 ms–2). How much is the pressure exerted by him on the floor?
3. A mercury barometer in a physics laboratory shows a 763 mm vertical column of mercury. Calculate the atmospheric pressure in pascal. [Given density of mercury, ρ = 1.36 × 10^4 kg m–3, g = 9.8 m s–2]
4.A force of 1200 N acts on the surface of area 10 cm
normally.
What would be the thrust and pressure on the surface?
5.The elephant weighs 20,000 N stands on one foot of area 1000
Cm2How much pressure would it exert on the ground?
6.The pressure of a gas contained in a cylinder with a movable
piston is 300 Pa. The area of the piston is 0.5 m
. Calculate the
force that is exerted on the piston.


Please help

Answer 1

Explanation:

Helicase unwinds the helix, and single-strand binding proteins prevent the helix from re-forming. ... Single-strand binding proteins coat the DNA around the replication fork to prevent rewinding of the DNA. Topoisomerase works at the region ahead of the replication fork to prevent supercoiling.