1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Acceleration of a body( negative velocity and speeding up)

  1. Nov 19, 2015 #1
    1. The problem statement, all variables and given/known data
    What is the acceleration of a body which is moving in opposite direction(assuming negative velocity) and is speeding up?

    2. Relevant equations
    acceleration=the rate of which an object changes its velocity

    3. The attempt at a solution
    In my opinion, an object moves with a negative velocity and is speeding up can be regard as having negative acceleration. This is what I learn from the notes provided on Physics Classroom. Is this correct?
     
  2. jcsd
  3. Nov 19, 2015 #2

    PeroK

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Yes. In this scenario velocity and acceleration are both negative.

    If the acceleration were positive, the object would slow down, stop instantaneously, then move with increasingly speed in the positive direction.
     
  4. Nov 19, 2015 #3
    So if the object is moving in opposite direction but it is slowing down, hence it has positive acceleration?
     
  5. Nov 19, 2015 #4

    PeroK

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Best to say "negative" direction. Yes. That would be positive acceleration.

    This is important because when you have problems involving gravity (or any force), you can take the positive direction to be upwards. In that case gravity is a negative acceleration. And, sometimes, you take downwards to be positive and gravity is a positive acceleration. So, you need to understand both cases.
     
  6. Nov 19, 2015 #5
    Alright. Thank you very much
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted