# Isaac physics help!!

Watch
Announcements
#1
Hi can someone help me with this kinematics questions I'm struggling with from Isaac Physics?
A lorry travelling along a narrow road with speed u1 applies its brakes to give a uniform deceleration of magnitude a1. At the same time a car, a distance d behind the lorry and travelling in the same direction with speed u2, applies its brakes to give a uniform deceleration of magnitude a2.

By considering the distance travelled by each vehicle before coming to rest, show that a collision will occur if a2≤ku2^2, and find k in terms of u1, d and a1.

Thanks!
Last edited by lilbaker_; 2 years ago
0
2 years ago
#2
Sorry you've not had any responses about this. Are you sure you've posted in the right place? Here's a link to our subject forum which should help get you more responses if you post there.
0
2 years ago
#3
This is my solution. First I found the distance to stop for both the lorry and the car. Then considered that a collision would occur if the stopping distance of the car plus the distance d is greater than the stopping distance of the lorry.

I tried uploading an image of my solution but it isn't working. Using suvat and algebraic manipulation, you should be able to get the answer!
0
2 years ago
#4
(Original post by JackMac2904)
This is my solution. First I found the distance to stop for both the lorry and the car. Then considered that a collision would occur if the stopping distance of the car plus the distance d is greater than the stopping distance of the lorry.

I tried uploading an image of my solution but it isn't working. Using suvat and algebraic manipulation, you should be able to get the answer!
Hi do you know the answer to this?
0
2 years ago
#5
(Original post by nooksnd)
Hi do you know the answer to this?
Sorry the photo's a little blurry

https://imgur.com/a/Y1xIM31
0
2 years ago
#6
(Original post by JackMac2904)
Sorry the photo's a little blurry

https://imgur.com/a/Y1xIM31
Thank you!
0
1 year ago
#7
this doesn't work?
0
X

new posts
Back
to top
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.

### Poll

Join the discussion

#### What support do you need with your UCAS application?

I need help researching unis (25)
13.66%
I need help researching courses (12)
6.56%
I need help with filling out the application form (9)
4.92%
I need help with my personal statement (76)
41.53%
I need help with understanding how to make my application stand out (44)
24.04%
I need help with something else (let us know in the thread!) (3)
1.64%
I'm feeling confident about my application and don't need any help at the moment (14)
7.65%