Finding time when you have initial velocity and position

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SUMMARY

The discussion focuses on calculating the time of flight for a test rocket launched from a 200.0-meter incline at an acceleration of 1.36 m/s², starting from rest. Key parameters include an incline angle of 35.0 degrees and gravitational acceleration of -9.8 m/s². The participant successfully calculated the maximum height of 124 meters and the final velocity at the end of the incline as 23.323 m/s. The challenge lies in determining the total time of flight using the derived equations of motion.

PREREQUISITES
  • Understanding of kinematic equations, specifically: x = xo + Vot + (0.5)at²
  • Knowledge of projectile motion principles, including initial velocity and angle of launch
  • Familiarity with trigonometric functions, particularly sine and cosine for angle calculations
  • Basic grasp of gravitational effects on motion in a vacuum
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  • Learn how to derive time of flight for projectile motion given initial velocity and angle
  • Study the application of kinematic equations in multi-stage motion scenarios
  • Explore the effects of air resistance on projectile trajectories
  • Investigate advanced projectile motion problems involving varying angles and accelerations
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oliampian
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***Sorry I meant to say finding time when you have initial velocity and position***
1. Homework Statement

A test rocket is launched by accelerating it along a 200.0-m incline at 1.36 m/s2 starting from rest at point A (the figure (Figure 1) .) The incline rises at 35.0 ∘ above the horizontal, and at the instant the rocket leaves it, its engines turn off and it is subject only to gravity (air resistance can be ignored).

Find the maximum height above the ground that the rocket reaches.
Find the greatest horizontal range of the rocket beyond point A.

Known:
Vo = 0 (because starting from rest)
aon incline = 1.36 m/s2
aoff incline = -9.8 m/s2
ramp distance = 200m
θ = 35°

Homework Equations


x = xo + Vot + (0.5)at2
V = Vo + at
V2 = Vo2 + 2aΔx

The Attempt at a Solution


I already found the first part, which turned out to be 124m when rounded to three sig figs.
I found through calculations that Vat end of incline = 23.323m/s:
using the V2 = Vo2 + 2aΔx
Vat end of incline = √(2(1.36m/s2)(200m))
Vat end of incline(x-component) = 23.323m/s(sin(35)) = 19.1050m/s
Distance in x-component = Dx = 200m(cos35) = 163.8304

So to find the total horizontal distance so far I have the equation:
x = 163.8304 + 19.105t - 0.5(9.8)t2

What I'm stuck on is trying to find the total time so I can plug that into the equation.
 
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oliampian said:
***Sorry I meant to say finding time when you have initial velocity and position***
1. Homework Statement

A test rocket is launched by accelerating it along a 200.0-m incline at 1.36 m/s2 starting from rest at point A (the figure (Figure 1) .) The incline rises at 35.0 ∘ above the horizontal, and at the instant the rocket leaves it, its engines turn off and it is subject only to gravity (air resistance can be ignored).

Find the maximum height above the ground that the rocket reaches.
Find the greatest horizontal range of the rocket beyond point A.

Known:
Vo = 0 (because starting from rest)
aon incline = 1.36 m/s2
aoff incline = -9.8 m/s2
ramp distance = 200m
θ = 35°

Homework Equations


x = xo + Vot + (0.5)at2
V = Vo + at
V2 = Vo2 + 2aΔx

The Attempt at a Solution


I already found the first part, which turned out to be 124m when rounded to three sig figs.
I found through calculations that Vat end of incline = 23.323m/s:
using the V2 = Vo2 + 2aΔx
Vat end of incline = √(2(1.36m/s2)(200m))
Vat end of incline(x-component) = 23.323m/s(sin(35)) = 19.1050m/s
Distance in x-component = Dx = 200m(cos35) = 163.8304

So to find the total horizontal distance so far I have the equation:
x = 163.8304 + 19.105t - 0.5(9.8)t2

Where does this equation come from? And when did gravity start acting sideways?

When the rocket leaves the ramp, the engines turn off, so the rocket just coasts until it lands.

What I'm stuck on is trying to find the total time so I can plug that into the equation.

When the rocket leaves the ramp, it acts like any other projectile. You have an initial velocity and an angle at which the rocket is traveling relative to the horizon.
 

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