A sharp knife can cut food much more easily because-
It produces greater force than blunt knife.
Its mass is less as the blade is thinner.
It produces greater pressure on the food.
Friction between the blade and food is reduced.
Pressure varies with force (F) as (providing area is same)
F
F2
What is the atmosphere compared with?
an ocean of water
a tightly packed envelope of air molecules
a tightly packed envelope of air
a balnket of air surrounding the Earth
1 Pascal is equal to :
1 Erg / m2
1 Dyne / m
1 Joule m2
1 Newton m-2
1kg m/s is equal to :
1 N s
1 N m
10 N s
A rubber sucker, when pressed on a surface sticks to it, because-
Gravitational pull acts on it
Atmospheric pressure acts on it
Rubber sucker has some glucine it.
None of these
The water supply from an overhead tank to the houses can be done becuse of which of the following ?
Difference in pressure
Gravitational force
Decrease of friction in pipes
Flow of liquid
A plastic ruler rubbed with wool attracts tiny bits of paper. Determine the force acting on the paper ?
Electrostatic force
Magnetic force
Mechanical force
Frictional force
Pressure at a certain depth (h1) in river is P1 and at another depth h2 (1) is P2, then :
P1= P2
P1>P2
P1
2
P1-P2 = atmospheric pressure
The speed of a falling body increases continuously. This is because :
No force acts on it
It is very light
Air exerts a frictional force along the direction of motion
The earth attracts it
