P8 - Moment, Centre of mass

Question 1

moment

Answer 1

turning effect of force

Question 2

increase moment by

Answer 2

-increasing size of force
+ distance from pivot

Question 3

load

Answer 3

weight of object

Question 4

effort

Answer 4

-force applied by person

Question 5

pivot

Answer 5

-point of moment

Question 6

force multiplier

Answer 6

-a lever used so that load can be moved by smaller effort

Question 7

Line of action

Answer 7

-line that force acts along

Question 8

moment equation

Answer 8

moment = force x distance

Question 9

gears

Answer 9

-multiply moment of engine force
- exert equal and opposite forces when edges meet

Question 10

Low gear = low speed

Answer 10

-small gear turns bigger one
-more force is needed
-force increases = larger moment of small gear
- turns slower

Question 11

High gear = high speed + low moment

Answer 11

-larger gear turns smaller one
-less force
-faster speed
-force is less = smaller moment

Question 12

centre of mass

Answer 12

-the point at which the mass of an object is concentrated

Question 13

where is the centre of mass on an symmetrical object

Answer 13

-along axes of symmetry
-diagonals meet
-midpoints

Question 14

when an object is freely suspended

Answer 14

-it rests with its centre of mass directly beneath point of suspension

Question 15

principle of moments

Answer 15

-if an object is not turning
-sum of clockwise moments = sum of anticlockwise

Question 16

When fores do not pass through a fixed point in an object

Answer 16

-they can turn the object about that point

Question 17

The parallelogram of forces

Answer 17

-geometrical method used to find resultant of 2 forces that don’t act along same line

Question 18

The parallelogram of forces - resultant size

Answer 18

-draw parallelogram
-length of diagonal

Question 19

resolving force

Answer 19

-finding perpendicular components that have a resultant force that is equal to the force

Question 20

To resolve a force in 2 directions

Answer 20

-draw rectangle
-diagonal represents force vector
-length of adjacent sides = vertical/horizontal components