# AS Physics - Moments and Couples HelpWatch

Thread starter 2 years ago
#1
Hi, would anybody be able to help me with the following question about moments and couples?

A door has a handle which is 0.8m from the hinge. What is the moment of the following forces applied to the handle about the hinge:
a) 12N at right angles to the door
b) 20N at 70° to the door
c) 100N at 25° to the door

Also the questions in the attachments. Thank you!
0
reply

#### Study help in partnership with Birmingham City University

2 years ago
#2
Moments is distance X force acting at 90 degrees.
If it's at an angle then resolve using Pythagoras or sin/cos rules to find the vertical and horizontal vectors and then multiple the distance by the vector acting at 90•
1
reply
4 weeks ago
#3
6a) force= 12N angle=90deg perpendicular distance= 0.8m moment= 12 x 0.8 x sin(90) = 9.6Nmb) force= 20N angle=70 deg perpendicular distance= 0.8mmoment= 20 x 0.8 x sin(70) = 15Nmc) moment= 100 x 0.8 x sin(25) = 33.8Nm
0
reply
X

Write a reply...
Reply
new posts

Latest
My Feed

### Oops, nobody has postedin the last few hours.

Why not re-start the conversation?

see more

### See more of what you like onThe Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

### University open days

• University of Bath
Undergraduate Virtual Open Day Undergraduate
Sat, 23 Feb '19
• Ravensbourne University London
School of Design, School of Media Further education
Sat, 23 Feb '19
• Leeds Trinity University
PGCE Open Day Further education
Sat, 23 Feb '19

### Poll

Join the discussion

Yes (13)
5.6%
No (219)
94.4%

View All
Latest
My Feed

### Oops, nobody has postedin the last few hours.

Why not re-start the conversation?

### See more of what you like onThe Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.