You are Here: Home >< Maths

# Work done against friction? Watch

1. A screw jack has a single start thread of pitch 6 mm and an
load and effort were taken during a test on the jack.
Load (kN) 0 1 2 3 4 5 6 7 8 9 10
Effort (N) 2.2 6.6 11.8 17.0 22.2 27.2 32.2 36.8 41.4 46.9 52.4
(a) Plot a graph of effort against load and from it, determine the
law of the machine.
(c) Plot a graph of efficiency against load and state whether the
machine is likely to overhaul.
(d) Calculate the theoretical limiting values of mechanical
tend towards these values.
(e) Calculate the work input and the work done against friction
when raising the 10 kN load through a height of 50 mm.

I am confused with the work done against friction, Is it same as work done in overcoming friction?
2. (Original post by TAREQ003)
A screw jack has a single start thread of pitch 6 mm and an
load and effort were taken during a test on the jack.
Load (kN) 0 1 2 3 4 5 6 7 8 9 10
Effort (N) 2.2 6.6 11.8 17.0 22.2 27.2 32.2 36.8 41.4 46.9 52.4
(a) Plot a graph of effort against load and from it, determine the
law of the machine.
(c) Plot a graph of efficiency against load and state whether the
machine is likely to overhaul.
(d) Calculate the theoretical limiting values of mechanical
tend towards these values.
(e) Calculate the work input and the work done against friction
when raising the 10 kN load through a height of 50 mm.
I am confused with the work done against friction, Is it same as work done in overcoming friction?
Work done against = work done to overcome, you are correct.
3. (Original post by HapaxOromenon3)
Work done against = work done to overcome, you are correct.
Thanks i done it

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: June 21, 2016
Today on TSR

### How to stand out in an Oxbridge interview

What makes you memorable?

### A pregnant woman visits me every night

Discussions on TSR

• Latest
• ## See more of what you like on The Student Room

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

• Poll
Useful resources

### Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

### How to use LaTex

Writing equations the easy way

### Study habits of A* students

Top tips from students who have already aced their exams

## Groups associated with this forum:

View associated groups
Discussions on TSR

• Latest
• ## See more of what you like on The Student Room

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

• The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE