Pakistan MCQs

Orbital objects still experience gravity.
They appear weightless because all parts accelerate together.

Field strength is force per unit mass.
G=20/4 = 5 N/kg.

Escape velocity depends on the body's mass and radius.
It is independent of the escaping object's mass.

Weight is W=mg.
W=8×9.8 = 78.4 N.

Density measures how much mass is contained in a given volume.
Its SI unit is kg/m³.

Density is mass divided by volume.
ρ=600/0.5 = 1200 kg/m³.

Pressure describes how force is distributed over a surface.
Its SI unit is the pascal.

Mass equals density times volume.
M=800×0.25 = 200 kg.

Pascal's principle is used in hydraulic machines.
The same pressure can produce different forces on different piston areas.

Pressure is force divided by area.
P=100/0.5 = 200 Pa.

Immersion displaces fluid and creates an upward resultant pressure force.
That force equals the displaced fluid's weight.

Force equals pressure times area.
F=5000×0.02 = 100 N.