FORMULAE

Question 1

moments

Answer 1

the moment of a force is the turning effect of a force

Question 2

moment

Answer 2

Fx

Question 3

perpendicular moment

Answer 3

Fdcosθ

Question 4

principle of moments

Answer 4

for a system to be balanced, the sum of clockwise moments must be equal to the sum of anticlockwise moments

Question 5

couple

Answer 5

a pair of equal and opposite forces which tend to produce rotation only

Question 6

torque

Answer 6

the turning effect of a couple

Question 7

CoG

Answer 7

the point through which gravity is thought to act

Question 8

density

Answer 8

ρ=m/V

Question 9

pressure

Answer 9

p=F/A

Question 10

pressure in fluids

Answer 10

Δp=ρgh

Question 11

upthrust

Answer 11

the resultant upwards force on an object in a fluid

Question 12

upthrust

Answer 12

W=ρAxg

Question 13

Work

Answer 13

Fd

Question 14

work at an angle

Answer 14

Fdcosθ

Question 15

energy

Answer 15

the stored ability to do work

Question 16

GPE

Answer 16

mgΔh

Question 17

kinetic energy

Answer 17

1/2mv^2

Question 18

power

Answer 18

ΔE/Δt or Fv or W/t

Question 19

Hooke’s law

Answer 19

F=kx

Question 20

stress

Answer 20

force per unit cross sectional area

Question 21

strain

Answer 21

extension per unit length

Question 22

young modulus

Answer 22

stress/strain = (Fl)/(Ax)

Question 23

elastic deformation

Answer 23

when the load is removed, the object will return to its original shape

Question 24

plastic deformation

Answer 24

when the load is removed, the object will not return to its original shape