Impulse: multiple choice question

AI Thread Summary
The discussion revolves around solving a physics problem related to impulse and collision. The user ZanyZoya initially calculated the force as 167,000 N but was informed that the correct answer is 83,000 N. The error stemmed from using an inappropriate equation for time estimation, as acceleration was not zero. Participants clarified that assuming constant acceleration is necessary for applying SUVAT equations effectively. Ultimately, ZanyZoya expressed gratitude for the guidance and indicated a better understanding of the problem.
zanyzoya
Gold Member
Messages
14
Reaction score
0
Member advised to use the formatting template for all homework help requests
Hi all
Can anyone please help me with Q14 (attached) as you can see I am getting 167000N however the correct answer is 83000N
Many thanks
ZanyZoya
 

Attachments

  • image.jpg
    image.jpg
    37.9 KB · Views: 448
Physics news on Phys.org
Your estimate of the time for the collision (t = d/v) is inappropriate. This equation is used if the acceleration is zero. Here this is clearly not the case. What is is the average acceleration of a car that comes to rest over a distance of 0.30 m when it has initial speed 10 m/s?
 
Hmm we can’t use suvat equations as acceleration is not constant, we could use average acceleration =change in velocity/time but we don’t know time... hmm
 
zanyzoya said:
Hmm we can’t use suvat equations as acceleration is not constant ...
You have to assume that the acceleration is constant, otherwise you cannot solve the problem. What you cannot assume is that the acceleration is zero, which is what you did initially. So yes, use the SUVAT equations.
 
Thanks for your help kuruman, I think I’ve got it now.
 
Thread 'Collision of a bullet on a rod-string system: query'

Thread 'Collision of a bullet on a rod-string system: query'

In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
View full post »

Similar threads

Gravitational equipotential multiple choice problem
Replies
4
Views
2K
Impulse integration for a Tennis Racket hitting a Tennis Ball
Replies
3
Views
1K
How Does Impulse Relate to Momentum Change in Physics Problems?
Replies
7
Views
2K
Momentum - Impulse collision to find initial speeds and directions
Replies
6
Views
2K
Projectile Motion Question (Envelope of trajectories) query
Replies
42
Views
2K
Horizontal impulse on a ball at rest on a plane (with friction)
Replies
14
Views
3K
Creating a solution for all the answer choices
Replies
8
Views
1K
Find the final velocity of the bobsled after the last bobsledder jumps in
Replies
38
Views
2K
About electricity and the EMF -- Multiple choice question
Replies
13
Views
8K
Multiple-Choice Questions on the Behaviour of Waves and Light 😁
Replies
5
Views
2K

Hot Threads

Recent Insights

Back
Top