You are Here: Home >< Physics

# 9.8ms^-2 (unsure of how we get 'per-second per-second' and what this means) Watch

1. Howdy .

So gravity has 9.8ms^-2

What does metres per-second, per-second mean when explaining this?

As with acceleration, I get that 4ms^-1 means an object is travelling four metres every second.

Thanks
2. (Original post by makin)
Howdy .

So gravity has 9.8ms^-2

What does metres per-second, per-second mean when explaining this?

As with acceleration, I get that 4ms^-1 means an object is travelling four metres every second.

Thanks
For your example then the velocity of the object increases by 4 m/s every second i.e if it starts at 0 m/s at t = 0 (v(0)) then v(1) = 4 m/s, v(2) = 8 m/s, v(3) = 12 m/s etc.
3. Acceleration is the change in velocity/time
Velocity is m/s and time is s
That means m/s (or ms^-1)/ s
Hence ms^-2
4. (Original post by makin)
Howdy .

So gravity has 9.8ms^-2

What does metres per-second, per-second mean when explaining this?

As with acceleration, I get that 4ms^-1 means an object is travelling four metres every second.

Thanks
Each second the velocity increases by 4m/s
5. The speed increase every second, so you know that after 1 second a object is falling at 9.81m/s
Acceleration is the change in velocity/time
Velocity is m/s and time is s
That means m/s (or ms^-1)/ s
Hence ms^-2
Ah, that makes sense. Thanks

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: May 12, 2016
Today on TSR

### What is the latest you've left an assignment

And actually passed?

### Simply having a wonderful Christmas time...

Discussions on TSR

• Latest
• ## See more of what you like on The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

• Poll
Discussions on TSR

• Latest
• ## See more of what you like on The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

• 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

Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.