Math Is Fun Forum

EMPhillips1989

Member

Registered: 2008-01-21

Posts: 40

Mechanics- Please help!!!!

so ive been having a problem with the following question:

A car initially at rest accelerates at a rate

determine the distance when the car comes to a hault.

so this is my attempt at answering the question

As

Integrating this with respect to time gives:

where c is a constant
At x=0, t=0, so c=0
As

Integrating this again with respect to time gives:

where d is a constant
At x=0, t=0,

which gives:

which gives the position in terms of time

For this sort of question am I supposed to find an exact distance in metres? The questions goes on to ask how long the cars cars been travelling and the maximum speed attained by the car.
Can anyone give me some idea as to what to do next if this method is correct
Please help!!!

JaneFairfax

Member

Registered: 2007-02-23

Posts: 6,868

Re: Mechanics- Please help!!!!

You have

It is 0 when t = 0; the next time u = 0 is when t = 60. So substitute t=60 into

to find how far the car travels. It is

.

The max speed of the car is

(when t = 30).

Last edited by JaneFairfax (2008-02-16 05:39:16)

EMPhillips1989

Member

Registered: 2008-01-21

Posts: 40

Re: Mechanics- Please help!!!!

thank you very much that really helped me!!!