# Im not sure if this is the correct formula for this question, corect me

1. Apr 15, 2007

### ImsoFly

Im not sure if this is the correct formula for this question, plz corect me

1. The problem statement, all variables and given/known data
hi this is the problem: the burning of the second stage of a two stage toy rocket takes the rocket from 12 m/s to 40 m/s in 5.0s. How far does the rocket during this time?

2. Relevant equations
would i use delta t= delta v/a ?

2. Apr 15, 2007

### neutrino

Yes, you would need to use that equation.

3. Apr 15, 2007

### ImsoFly

Thanks neutrino.. but would i do (40-12) to find the velcoity?

4. Apr 15, 2007

### neutrino

What are the 'knowns' in $$\Delta t = \frac{\Delta v}{a}$$? Substitute them and find the unknown.

5. Apr 15, 2007

### ImsoFly

the knowns are velocity and acceleration, yeah i know that you substitute them but would i do (40-12) to find the velcoity?
so like for (40-12) do i plug that in velocity together?

Last edited: Apr 15, 2007
6. Apr 15, 2007

### neutrino

Delta v is change in velocity = Final velocity - Initial Velocity = 40-12.

7. Apr 15, 2007

### ImsoFly

Yeah, so it's 23 but i was just saying...how would i put that in the formula in the proper way...

delta t= delta v/a, delta t= (40-12)/5.0s, delta t =28m/s /5.0s = 5.6s
therefore the rocket traveled for 5.6 s?

8. Apr 15, 2007

### neutrino

Units are important physics, and the Second is a unit of time.

It has already been stated in the problem that the rocket has been moving for 5 seconds when it's speed changed from 12 to 40 m/s. Acceleration is a measure of how velocity changes with time.

9. Apr 15, 2007