You are Here: Home >< Physics

1. This question seems really easy but for some reason I can't work it out. The mark scheme and examiners report are no help because it's a multiple choice question.

question is attached or here.

thanks
Attached Images

2. I think the simplest way to get the marks is by recognising that impulse and change in momentum are the same thing.

http://www.physicsclassroom.com/clas...lse-Connection

impulse is Force x Time

so you can read off the change in momentum from the graph and the time taken and get the force from that (making sure to convert to SI units first)
3. (Original post by Joinedup)
(making sure to convert to SI units first)
That's why I couldn't get it, I didn't realize time was in milliseconds and not seconds! What a silly error!
4. FΔt = mv
F=(0.4--0.6)/(4x10^-3)
F=1/0.004
F=250N
5. (Original post by klosovic)
This question seems really easy but for some reason I can't work it out. The mark scheme and examiners report are no help because it's a multiple choice question.

question is attached or here.

thanks
First thing to always do is to check the axis and make sure the units are correct, here the time is in milliseconds so we mulitplay by x10^-3 for any calculation.

Now, Newton's second law states that Force is directly proportional to the rate of change of momentum. THe y-axis is momentum and the change is 1 (difference between 0.4 and -0.6).

We divide this by the time taken for the change in momentum to occur which is 2x10^-3 which is equal to 250N.

I think the main bit to remember here is the axis units and also that force = rate of change of momentum.
6. Conversion is very important
All units must be SI units

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: April 6, 2016
Today on TSR

### Does race play a role in Oxbridge admissions?

Or does it play no part?

### The worst opinion about food you'll ever hear

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
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

Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.