Acceleration and velocity

  • Thread starter bigzee20
  • Start date
  • #1
bigzee20
25
0

Homework Statement


A plane is moving at 270 m/s accelerates at 28 m/s ^2 for 9.8s. How far would it have traveled in the time.


using vi + a(t) i was able to get its final velocity 544.4m/s but when i multiply it by 9.8s it tells me that is wrong what am i doing wrong? thanks
 

Answers and Replies

  • #2
heth
108
0

Homework Statement


A plane is moving at 270 m/s accelerates at 28 m/s ^2 for 9.8s. How far would it have traveled in the time.

using vi + a(t) i was able to get its final velocity 544.4m/s but when i multiply it by 9.8s it tells me that is wrong what am i doing wrong? thanks

For what length of time does the plane travel at a speed of 544.4 m/s?
 
  • #3
bigzee20
25
0
9.8s but when i multiply it by 544.4 m /s its wrong??
 
  • #4
heth
108
0
9.8s but when i multiply it by 544.4 m /s its wrong??

What speed did the plane have at the start of the 9.8s? Try doing a before and after sketch with the plane's speed labelled each time.
 
  • #5
bigzee20
25
0
Iam still confused lol
 
  • #6
heth
108
0
Iam still confused lol

a. What speed was the plane going at right at the start of the question?

b. What speed was the plane going at right at the end of the question, 9.8 s later?

c. What do you think it was doing in between :-)

(Once you've got that conceptually, you can start to think about distance. If you just plug and chug with an equation for the distance right now, you'll be confused about a lot of things later in your course.)
 
  • #7
bigzee20
25
0
I got it man !!!!! woot.
Here it is d = Vi(t)+1/2a(t)^2
therefore 270(9.8) + 1/2(28)(9.8)^2
= 3990.56 m
THANKS heth
 
  • #8
heth
108
0
Nice one! The key is realising that the plane's velocity is changing all the time, so you can't use an equation that assumes the velocity is constant.
 

Suggested for: Acceleration and velocity

  • Last Post
Replies
9
Views
2K
  • Last Post
Replies
5
Views
1K
  • Last Post
Replies
1
Views
1K
  • Last Post
Replies
2
Views
871
  • Last Post
Replies
9
Views
2K
  • Last Post
Replies
5
Views
2K
  • Last Post
Replies
3
Views
1K
  • Last Post
Replies
1
Views
2K
  • Last Post
Replies
8
Views
6K
  • Last Post
Replies
1
Views
1K
Top