force & pressure

force is push or pull on an object that can

• change the state of mothion

• change the shape of the object

• change the direction of motion

• be added with common algebra

pressure is

• product of force and area

• ratio of force and area

• the effect of force

• ratio of the product and quotient of force and area

S.I.unit of force is

• N/m²

• Pa

• N

• kgf

which one exerts more pressure on ground?

• an elephant

• a boy

• girl wearing high heels

• a skater

atmospheric pressure is -------------

• more on the mountains

• less on the mountains

• less on the surface of water

• less under the depth of sea

The force that opposes the relative motion between the two surfaces

• gravitational force

• friction

• magnetic force

• electrostaic force

Select the methods to reduce friction

• stream lining

• spiking

• oiling

• using sand

which friction is maximum?

• static friction

• sliding friction

• rolling friction

• sliding friction = rolling friction

which of the following is not a streamlined body?

• shape of an aeroplane

• shape of a bird

• shape of a submarine

• shape of human body

atmoshperic pressure

• increases with height

• decreses with height

• always remains the same

• always greater than that on the surface of sea