Help Solving air drag projectile problem

AI Thread Summary
The discussion revolves around solving a projectile motion problem affected by air drag, with the user attempting to manipulate equations to find the time of flight. They provide a series of mathematical transformations but express confusion at a certain step in the process. A request is made for the original problem statement to clarify the context and assist in finding a solution. The user specifically seeks a formula for calculating the time of a projectile launched from ground level or a height, factoring in air resistance. The conversation highlights the challenges of incorporating air drag into projectile motion calculations.
Matt Jacques
Messages
81
Reaction score
0
Since my other thread is lacking attention, perhaps it is more suitable here:

I inserted some fixed constants and multiplied out

(48/.5)(1-^e-.5t)(sin 45) + (9.8/.25)(1-(.5t) - e^-.5t) = 0

(96 - 96e^-.5t)(sin 45) + 39.2(1-(.5t)-e^-.5t) = 0

67.88 - 67.88^e-.5t + 39.2 - 19.6t - 19.6e^-.5 = 0

107.2 - 87.48e^-.5t - 19.6t = 0

107.2 - 19.6t = 87.48^e-.5t

log(107.2 - 19.6t) = log(87.48^e-.5t)

log107.2 - log19.6t = -.5tLog(87.48)

2.030194 - log19.6t = -.5t(1.94198)

1.045463 - log19.6t = -.5t

-(1.045463 - log19.6t = -.5t)

-1.045463 + log19.6t = .5t

log19.6t = .5t + 1.045463

10^(.5t + 1.045463) = 19.6t

This is where I am stuck.
 
Physics news on Phys.org
Matt,

Could you post the original problem, or a link to your other thread? I don't see what you're trying to do with this.
 
Thread 'Variable mass system : water sprayed into a moving container'

Thread 'Variable mass system : water sprayed into a moving container'

Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
View full post »

Thread 'Struggling to understand the concept of this question (ice cube in water optics question)'

TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
View full post »

Similar threads

Projectile Motion -- Help please understanding these basic problems
Replies
4
Views
1K
Conservation of energy problem (projectile with air drag)
Replies
2
Views
3K
Need help solving a tricky projectile motion problem
Replies
11
Views
2K
Calculating the final velocity of a compressed-air launched projectile
Replies
4
Views
12K
Solving the Projectile Motion Problem With Air Drag
Replies
3
Views
2K
Projectile Problems: Range, Time & Theta C (6 Sig Digits)
2
Replies
53
Views
7K
Can Physics Equations Help Solve Real-Life Motion Problems?
Replies
6
Views
11K
Help with a cartesian problem to find a geocache.
Replies
1
Views
4K
Help Solving Failed Physics Test Questions
Replies
4
Views
9K

Hot Threads

Recent Insights

Back
Top