Question

sorry to keep posting this, but I have an assignment based on these problems (same equations different numbers) due in a couple hours.

A rocket is launched at an angle of 42◦ above the horizontal with an initial speed of 76 m/s. It moves for 9 s along its initial line of motion with an acceleration of 29 m/s^2. At this time
its engines fail and the rocket proceeds to move as a projectile.
The acceleration of gravity is 9.8 m/s^2.

a.) Find the maximum altitude reached by the rocket.
b.) What is its total time of flight?
c.) What is its horizontal range?

I know how to find these with constant acceleration (I think) but with the increasing acceleration I'm not sure.

Answers are:

a.) 3837.91 m
b.) 59.9965 s
c.) 14152.7 m

Need to know how to solve, thank you.

Answer 1

Do the prblem in two steps:
(1) constant acceleration phase (engine on)
(2) gravity acceleration only (engine off)

The finsl conditions at the end of phase 1 become the iunitial conditions for phase 2.

Answer 2

okay, how do I do step 1? I think if I could figure out how to get to the engine off phase i could solve, as I've done similar problems with just gravity and constant acceleration.

Thanks.