Statics

Question 1

What is the formula for weight?

Answer 1

Mass x gravity

Question 2

What is the formula for force?

Answer 2

Mass x acceleration

Question 3

What are concurrent forces?

Answer 3

All forces act on a single point.

Non-concurrent- do not act on a single point

Question 4

What are non-concurrent coplanar?

Answer 4

Force act in different lines but only on one plane.

Two dimensions only.

Question 5

What can a vector represent?

Answer 5

Anything that has magnitude (size) and direction.

Question 6

What is scalar?

Answer 6

If a quantity has magnitude (size) but no direction.

Question 7

What is the equation for moment?

Answer 7

Force x distance

Question 8

What is a static equilibrium?

Answer 8

Any mass that has no resulting force or moment acting on it. (but all forces must be concurrent)

(D’Alamberts principle)- moments are equal either side

Question 9

What is the formula for distance of centre of gravity from datum point?

Answer 9

Total moment / total weight

Question 10

What is hookes law?

Answer 10

When an elastic object is stretched and the extension is directly proportional to the amount of force applied.

F = k x e

Force = spring constant x extension

Question 11

What are direct forces?

Answer 11

Tensile and compressive forces

Question 12

What is the formula for stress?

Answer 12

Stress = force/area

Question 13

What is the fundamental unit of stress?

Answer 13

Pascals (N/m2)

Question 14

What is ultimate tensile stress?

Answer 14

When a material is stretched until it breaks.

Ultimate tensile stress = maximum force applied / original area

Question 15

What is the formula for strain?

Answer 15

Strain = deformation / length

Question 16

What is the safety factor?

Answer 16

Ultimate tensile stress / max allowed

Question 17

What is ultimate tensile stress?

Answer 17

When a material is stretched until it breaks.

Ultimate tensile stress = maximum force applied / original area

Question 18

What is the formula for strain?

Answer 18

Strain = deformation / length

Question 19

What is the safety factor?

Answer 19

Ultimate tensile stress / max allowed

Question 20

What is stiffness?

Answer 20

The ability to resist deformation due to an applied force.

Stiffness = force applied / deformation

Question 21

What is the formula for shear stress?

Answer 21

Force / area

Question 22

What is deformation?

Answer 22

When a load is applied to a material and it changes shape.

Question 23

What is elastic deformation?

Answer 23

Shape which deforms but returns to its original shape.

Permanently deforms is called plastic deformation.

Question 24

What happens to volume when a gas changes to a liquid?

Answer 24

Very large reduction in volume.

Question 25

What happens to volume when a liquid changes to a solid?

Answer 25

Relatively small decrease or increase in volume.

Question 26

What is the formula for density?

Answer 26

Density = mass / volume

Question 27

What is the formula for pressure?

Answer 27

Pressure = force / area

Question 28

What happens to the pressure exerted by a fluid?

Answer 28

Will always act at right angles to any surface in contact with the fluid.

Question 29

What happens to pressure of a fluid with depth?

Answer 29

Pressure increases with depth.

Question 30

What is absolute pressure?

Answer 30

Ambient pressure added to the gauge pressure.

Question 31

What is the formula for pressure in liquids?

Answer 31

Pressure in liquids = density x height x gravitational acceleration

Question 32

What is the rule form fluid transmission (putting pressure into a container of liquid)?

Answer 32

Pressure at every point is increased by the same amount.

Question 33

What is the formula for load?

Answer 33

Load = pressure x area

Question 34

What is Archimedes principle?

Answer 34

A body in fluid experiences an upthrust equal to the weight of fluid it displaces.

Question 35

What is the formula for relative density for bodies in water?

Answer 35

Relative density = weight of solid / upthrust

Question 36

What does a hydrometer measure?

Answer 36

Relative density.

Question 37

What does a piezometer measure?

Answer 37

Pressure of liquids in pipes.