moments

Question 1

what is a moment in simple terms?

Answer 1

turning effect of a force around a pivot point

Question 2

why is understanding moments important?

Answer 2

studying balance, stability and rotational motion

Question 3

what causes an object to turn?

Answer 3

a force or system of forces

Question 4

what is the definition of a moment?

Answer 4

a moment is the product of the force and perpendicular distance from the pivot

Question 5

what is the equation of moment?

Answer 5

force x perpendicular distance

Question 6

what is the pivot point?

Answer 6

the point around which the object can rotate or turn

Question 7

where is pivot on a seesaw?

Answer 7

directly in the middle

Question 8

what direction can be moments in?

Answer 8

moments can be clockwise or anticlockwise

Question 9

what does the direction of the moment depend on?

Answer 9

the direction of the force relative to the pivot

Question 10

what is the lever arm?

Answer 10

perpendicular distance between the line of action of the force and the pivot,
it directly affects the magnitude of the moment

Question 11

what does a longer lever arm produce ?

Answer 11

larger moments for the same force

Question 12

what is the unit of moments

Answer 12

newton metre (NM)

Question 13

what is the principle of moments?

Answer 13

for an object to be balanced the total clockwise moment must be equal to the total anti clockwise moment

Question 14

total clockwise moment =

Answer 14

total anticlockwise moment

Question 15

what do spanners and levers use?

Answer 15

both use moments

Question 16

what are spanners used for?

Answer 16

to turn nuts and bolts, if you need to undo a nut that is very tight you can use a short spanner and apply a large force or use a long spanner and apply small force

Question 17

why would you use a longer spanner?

Answer 17

using the longer spanner increases the distance from the pivot, this reduces the amount of force needed to undo the nut from the bolt

Question 18

what does a lever consist of?

Answer 18

a pivot, effort, load

Question 19

what are some examples of effort pivot load

Answer 19

seesaw, crowbar, scissors

Question 20

what are some examples of pivot load effort

Answer 20

wheelbarrow, nutcracker

Question 21

what are some examples of pivot effort load

Answer 21

tweezers, cooking tongs

Question 22

explain example of removing lid of paint can in terms of levers

Answer 22

• removing lid requires a large force on lid
• screwdriver acts as a lever
  -pivot is the edge of a can
  -very close to where the strong push is needed to lift the lid to open the can
  -screwdriver with long handle is best because you can push down on handle of screwdriver with a small force and open can

Question 23

how are moments used in engineering?

Answer 23

engineers use moments extensively in designing structures, bridges and machines. calculating and considering moments makes sure the safety and stability of constructions

Question 24

how is equilibrium achieved?

Answer 24

when an object is balanced and does not rotate

Question 25

why are moments important in rotational motion

Answer 25

helps explain how objects rotate and how energy is transferred in systems involving rotation