T13- Forces In Action

Question 1

What is a moment ?

Answer 1

The turnign effect of a force

Question 2

how to calculate moment ?

Answer 2

Moment (Nm) = Force(N)* Distance (M)
Newton metres not NEWTON/ ETRE .
-When calculating a momet , the distance HAS to be perpendicular to the line of action of the force too the pivot .

Question 3

Check sheet of the reallly bad drawn spanner nut

Answer 3

The turnign effect of the force is centered arounf the PIVOT , which is at the CENTER of the nut .

-A force od 50 N is being applied ,
the ditanc ebetween the line of action of the FORCE to the PIVOT is 0.3m and this is perpendiviular to the lilne of action of the force to thep ivot .
-So the MOMENT IS 502 IS 0.3M = 15Nm

Question 4

WHAT IF it is at angle not perpedicular tho

Answer 4

We cant usr this distance chekc the sheet
-has to be the perpendicular distance .

Question 5

A sesaw is abalanced about the pivot in the center

Answer 5

Each person is applying a momet due to their weight (the forceo f gravity acting ont heir own mass .)

-Person in the righ tis applying moment in the clockwise direction EXAMPL ECLOCKWISE MOMENT .
-Perosn on THE left is applying a moment in the clockwise direction CLOCKWISE MOMET .
-Person on lweft applying moment in the antilcolckwise direction ANTICLOCKWIDE MOEMT .

-aS THE SEASW IS ABALNCED
cockwise moment =anticlcokwise moemt
-We can sue this to calculate the force or the disrance from the pvito

Question 6

example

Answer 6

person b is applying a force of 50n and 0.7m from thepiot .
person a applying force 500n calculate distance persona should be so seesaw is abalnced
CHECK SHEET .

Question 7

Why objects topple

Answer 7

block on flat surface .
-The weight of the block (force due to gravity)
acts directlyd own fromt he center of mass .

-IId you tilit the block
-There somes a point where the line of action of the weight lies outisde the base of the obejct .
-Now there is a resultant (unbalanced) moment acting on the block .
-Causing the block to topple

Question 8

Symmetrical object center of mass

Answer 8

-TGhe center of mass is along the lline of symmetry where the two lines interect is the center of graviry .

Question 9

cetter of mass for an asymmertrical object

Answer 9

need stand clampa ndboss nd in the clamp need a cork with a pin .
-Also nee da plub line ..

Question 10

s1 Asyymetrical

Answer 10

mark two holes in the object

Question 11

S2 symmetrical

Answer 11

Hold it up by the first point of suspension .
-Hang the plumbline infront of it .
-Mark thrr two points along this line then join the two points together .

Question 12

s3 asymmetrical

Answer 12

then hang the object up y the second point and then repeat the stage .

Question 13

s4 assymetrical objects

Answer 13

where the two lines interesect is the center of gravity .

Question 14

s5 asymmetrical objects

Answer 14

if the oject balances on your fingerr then we have found the objects center of gravity .

Question 15

check sheet for resolving forces

Answer 15

watch video on resoling ofrces and exa practice question in video , answer it .