Forces, Density, And Pressure

Question 1

Centre of gravity

Answer 1

The point in which the whole weight if the object appears to act

Question 2

Moment

Answer 2

The force multiplied by perpendicular distance

Question 3

Couple

Answer 3

A pair of equal forces acting parallel to each other in opposite directions

Question 4

Torque

Answer 4

Product of one of the forces and perpendicular distance

Question 5

Principle of moments

Answer 5

Clockwise moments must be equal to anticlockwise moments

Question 6

Density

Answer 6

Mass per unit volume

Question 7

Pressure

Answer 7

Force per unit area where force acts perpendicularly to the area

Question 8

Fluid pressure

Answer 8

Pressure caused by weight of liquid above a small area if that depth

Question 9

Upthrust

Answer 9

Force in a submerged principal

Question 10

Archimedes’ principle

Answer 10

Upthrust acting on an object immersed in a fluid is ewual to the weight of the fluid displaced

Question 11

How is archimedes’ principle mathematically true

Answer 11

Pressure increases with depth, creating a pressure difference between the top and bottom of a submerged object. This difference generates an upward force, the buoyant force. The magnitude of this force is directly proportional to the weight of the fluid column above the object, which is equivalent to the weight of the displaced fluid. Therefore, the buoyant force is equal to the weight of the displaced fluid, confirming Archimedes’ principle.

Question 12

2 factors affecting fluid pressure

Answer 12

• density: denser fluid has more mass with the same volume which means that it will result in more weight, hence more pressure
• depth: the deeper you go, the higher the pressure because weight if fluid increases as you go down