- #1
Malor
- 7
- 0
Hi, it's my first time on these forum, so I hope that I made this post correctly.
I have an example solution to this problem using tensors and matrices ^^ but I wanted to solve the problem in a different way and would like some feedback on whether or not this solution is correct.
A gun shoots a projectile vertically into the air with an exit velocity of vvert=60ms-1 (assuming the nozzle is at sea level). Calculate the distance Δs, between the starting point and landing point of the projectile. Do this for the latitudes 0° and 51°. (neglect cascading effects)2. The attempt at a solution
Getting the time t for the whole process is a no-brainer:
v(t) = 0 = vvert-gt , g = const. => t1 = 6.1s => ttotal = 12.2s
Now to calculate Δs:
We assume that the Earth is an ideal globe, with a radius r = 6370000km. Basic geometry tells us that the distance from the axis of rotation is
R = sqrt(h(2r-h)) => R = sqrt(r²-r²sin²(α)) , α...latitude => R = r*cos(α)
The circumference of r(t) is the gives us the orbital velocity vB = const.:
r(t) = r + ∫v(t)dt
2∏r(0)/d = vB , d...day
vB is constant => ω can not be constant:
ω(t) = vB1/vB2*ω1 = u1/u2*ω1 = r/r(t)*ω1 (R1/R2 = r1/r2)
Angular acceleration: w'(t) = - (r*v(t))/(r+∫v(t)dt)² * ω1
Δω = ω1 ∫ -(r*v(t))/(r+∫v(t)dt)² dt
Δs = Δω*R*t = r*cos(α)*t*ω1 ∫ -(r*v(t))/(r+∫v(t)dt)² dt
Thank you for your troubles.
I have an example solution to this problem using tensors and matrices ^^ but I wanted to solve the problem in a different way and would like some feedback on whether or not this solution is correct.
Homework Statement
A gun shoots a projectile vertically into the air with an exit velocity of vvert=60ms-1 (assuming the nozzle is at sea level). Calculate the distance Δs, between the starting point and landing point of the projectile. Do this for the latitudes 0° and 51°. (neglect cascading effects)2. The attempt at a solution
Getting the time t for the whole process is a no-brainer:
v(t) = 0 = vvert-gt , g = const. => t1 = 6.1s => ttotal = 12.2s
Now to calculate Δs:
We assume that the Earth is an ideal globe, with a radius r = 6370000km. Basic geometry tells us that the distance from the axis of rotation is
R = sqrt(h(2r-h)) => R = sqrt(r²-r²sin²(α)) , α...latitude => R = r*cos(α)
The circumference of r(t) is the gives us the orbital velocity vB = const.:
r(t) = r + ∫v(t)dt
2∏r(0)/d = vB , d...day
vB is constant => ω can not be constant:
ω(t) = vB1/vB2*ω1 = u1/u2*ω1 = r/r(t)*ω1 (R1/R2 = r1/r2)
Angular acceleration: w'(t) = - (r*v(t))/(r+∫v(t)dt)² * ω1
Δω = ω1 ∫ -(r*v(t))/(r+∫v(t)dt)² dt
Δs = Δω*R*t = r*cos(α)*t*ω1 ∫ -(r*v(t))/(r+∫v(t)dt)² dt
Thank you for your troubles.