# Homework Help: Find the powers p and q that make this equation dimensionally consistent

1. Aug 26, 2010

### swatmedic05

Acceleration is related to velocity and time by the following expression: A=V^p t^q

Find the powers p and q that make this equation dimensionally consistent.

2. Aug 26, 2010

### rock.freak667

So what dimensions are A, V and t ?

When you get that, then equate exponents.

3. Aug 26, 2010

### swatmedic05

I new to physics I still dont get what I have to do

4. Aug 26, 2010

### rock.freak667

Alright then. Lets start simple.

What are the units for acceleration (A)?

What are the units for velocity (V)?

What are the units for time (t) ?

5. Aug 26, 2010

### swatmedic05

A= [l]/[t]^2
v= [l]/[t]
t=[t]

6. Aug 26, 2010

### rock.freak667

Good. So in A=Vptq, on the left side we have

LT-2

and on the right we have

(LT-1)p(T)q

What does the right side give?

7. Aug 26, 2010

### swatmedic05

I just got it now.... Thank you for explaining it better to me. I appreciate all your help