Physics URGENT HELP!!!!! GCSE Watch
- Thread Starter
- 15-06-2016 13:44
Online21ReputationRep:Very Important Poster
- Very Important Poster
- 15-06-2016 16:31
- 15-06-2016 22:08
I think the answer is 3000 N
- 15-06-2016 22:19
So you know that F=M * A, so if you have been given the mass of car and caravan, just minus the mass of the car to find the mass of the caravan. Then you have been given the deceleration so just times 1000 (the mass of the caravan) by 3 (deceleration) which is 3000 N so you were right. I am a bit confused however why the deceleration wouldn't be converted to minus when put in the calculation as acceleration! if you need more help just watch this, https://www.youtube.com/watch?v=6GYx...E3947A&index=1
Literally it has saved my life!
- 15-06-2016 22:21
1. i first subtracted the mass of the caravan and car which is 1000kg
2. i used the formula force = mass x acceleration
-> force = 1000kg x 3 m/s^2 making the answer 3000N
i could be wrong tho lol
- 15-06-2016 22:35
=2000 x 3
=6000N to decelerate both.
But we know the car is already providing 4000N. So the caravan is contributing 2000N of braking force.
The trick to questions like this is to define your 'body.'
Hope that helps.
(p.s. it gets a little complicated to treat the caravan separately, because there are forces from the car acting upon it which would need calculating. Although it's possible to do it this way, It is best to treat both as a single decelerating system.)Last edited by physicist 2016; 15-06-2016 at 22:40.