Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
6 Cards in this Set
- Front
- Back
|
What are moments?
|
Turning effect of a force (e.g. force on nut of spanner)
UNITS ARE Nm |
|
|
What does the principle of moments say?
|
If an object is balanced then:
Total anti-clockwise moments = Total clockwise moments |
|
|
How can principle of moments be used?
|
To help solve problems where forces acting on a balanced object are equal
|
|
|
Your younger brother weighs 300N and sits 2m from pivot of seesaw. If you weigh 700N where should you sit to balance?
|
moment = F x distance
anticlockwise moment = clockwise moment 300 x 2 = 700 x ? distance = moment / F 0.86 m = 600/700 |
|
How do you work out the tension on supporting cables if an object is placed nearer to one end (see diagram)
|
Treat one end as a pivot:
TA x 6 (6m from B) = 900 x 4 TA = 3600/6 = 600N so 900N = TA + TB so 900 = 600 (TB) = TA |
|
What happens if the moments are not equal?
|
turn clockwise due to resultant moment force 20N
|
