Turn on thread page Beta
 You are Here: Home >< Maths

Mechanics help please watch

Announcements
1. Me again, finding M2 tricky

When t=0 a particle P is at rest at point A, whose position vector relative to a fixed point o is r= (3i+4j)m. P moves with acceleration a ms^-2 at time t seconds given by a =5ti.
Find the distance P moves between t=1 and t=2

Made an attempt, integrated a twice to get r , but I didn't get the right result, not sure if this was an error in working or if I used the wrong method entirely. Thanks in advance
2. (Original post by Apagg)
Me again, finding M2 tricky

When t=0 a particle P is at rest at point A, whose position vector relative to a fixed point o is r= (3i+4j)m. P moves with acceleration a ms^-2 at time t seconds given by a =5ti.
Find the distance P moves between t=1 and t=2

Made an attempt, integrated a twice to get r , but I didn't get the right result, not sure if this was an error in working or if I used the wrong method entirely. Thanks in advance
a=5ti
v=∫(a)dt
v=2.5t²i+ci+cj
t=0 v=0
0=ci+cj
.:.v=2.5t²i

r=∫(v)dt
r= (5/6)t³i+ci+cj
t=0 r=(3i+4j)m
ci+cj=3i+4j

.:. r=[(5/6)t³i+3i+4j]m

t=1 r=[35/6i +4j]m
t=2 r=[92/3i+4j]m

Distance between= [(92/3i+4j)-(35/6i +4j)]m
=(5 5/6i)m
=5 5/6m

Turn on thread page Beta
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: November 18, 2005
Today on TSR

Official 2019 Cambridge Interview Thread

Discuss upcoming interviews...

University open days

• Heriot-Watt University
School of Textiles and Design Undergraduate
Fri, 16 Nov '18
• University of Roehampton
Sat, 17 Nov '18
• Edge Hill University
Faculty of Health and Social Care Undergraduate
Sat, 17 Nov '18
Poll
Useful resources

Make your revision easier

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

Create your own Study Planner

Never miss a deadline again

Thinking about a maths degree?

Chat with other maths applicants

Can you help? Study help unanswered threads

Groups associated with this forum:

View associated groups

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