- #1

simphys

- 324

- 46

- Homework Statement
- A rocket is launched from the surface and reaches a maximum height of 960m. The rocket’s engine gives an 16m/s^2 upward acceleration during time T. After that time T the rocket is in free fall.

What must be the value of T in order for the rocket to reach the required altitude(of 960m)?

- Relevant Equations
- Getting the solution was no problem.(steps included in picture)

My question is how I could go about reasoning whether the solution of the problem makes sense without actually looking at the solution in the back.

Here f.e. T=6.75 for the ‘first’ stage, how can I reason/evaluate this without looking at the solution?

My guess is that I could compare it to the time interval of the free fall motion(stage2).

Would that be enough to let it make ‘sense’?

As we know that stage 1 has an acceleration of 16m/s^2 and free fall one of 9.81m/s^2. Then.. is it sufficient to reason that the time needed to complete stage 1 will be less than the time need to go from the start of free fall to the maximum altitude?

THANKS IN ADVANCE!

Would that be enough to let it make ‘sense’?

As we know that stage 1 has an acceleration of 16m/s^2 and free fall one of 9.81m/s^2. Then.. is it sufficient to reason that the time needed to complete stage 1 will be less than the time need to go from the start of free fall to the maximum altitude?

THANKS IN ADVANCE!