Finding time when you have initial velocity and position

AI Thread Summary
To find the total time for the rocket's flight after leaving the incline, one must consider its initial velocity and the effects of gravity. The rocket accelerates along a 200.0-m incline at 1.36 m/s², reaching a velocity of 23.323 m/s at the end of the incline, with a horizontal component of 19.105 m/s. After the engines turn off, the rocket behaves like a projectile, and gravity acts downwards, not sideways. The equation for horizontal distance combines the initial horizontal position, the horizontal velocity, and the effect of gravity over time. The key challenge is determining the total time of flight to complete the calculations for maximum height and horizontal range.
oliampian
Messages
6
Reaction score
0
***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.
 
Last edited:
Physics news on Phys.org
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.
 
I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
Thread 'A cylinder connected to a hanging mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top