Search results

1. Question on significant digits

Hi all. Let's say I have a set of data as follows (the mass of a sample of some chemical measured several times): 23.132 g 24.532 g 21.532 g 22.853 g 23.193 g (I just made that data up, but imagine that a analytical scale put out those numbers, exactly as shown, on its display.)...
2. Projectile Motion of launched ball

And where exactly did you modify it so it takes into account that gravity is pointing down? Edit, nevermind I see it. Thanks so much!
3. Projectile Motion of launched ball

No, but I know your equation is right, I simulated it.
4. Projectile Motion of launched ball

Thank you! It works now. Why is it not negative? And thanks again for all your help! It's clear now!
5. Projectile Motion of launched ball

According to your equation, I did this: Solve[0 == -(14 + 0.08 (-9.81)) + 10 u - 0.08 (-9.81) u^2, u] It spits out: {{u -> -13.9493}, {u -> 1.20716}} So far, I have 3 different sets of answers (6 answers in total) which all seem to work out. There should be only 2 solutions. Which one is right?
6. Projectile Motion of launched ball

Well sorrrrryyyyyy! Can you explain how you got from the top two equations to the quadratic equations? I tried it but I'm getting imaginary numbers.
7. Projectile Motion of launched ball

I put in: Solve[25^2 == (10/t)^2 + ((14 + 4.9 t^2)/(t))^2, t] It gave me: {{t -> -4.43739}, {t -> -0.791265}, {t -> 0.791265}, {t -> 4.43739}} These two are the right answers for t: {t -> 0.791265}, {t -> 4.43739} All I want to know is how to get to this point on paper.
8. Projectile Motion of launched ball

Ok now I have all the equations I need: V[x]^2 + V[y]^2 = 25^2 = 625 14 = V[y] \Delta t - 4.9 t^2 10 = V[x] \Delta t I know how to do simultaneous equations. I have to solve for V[x] and V[y] from the second and third equations and plug that into the first one to get time. Then I can...
9. Projectile Motion of launched ball

[/B] That's exactly what I did but I don't know where to go from there.
10. Kinematics Equations (2 Problems!)

Haha! I know how that is... The answer is NO. This is because x could have a positive displacement and could also have a negative acceleration (slowing down) at the same time. Example, you roll a ball on the floor. It moves away from you (positive displacement) but is also slowing down...
11. Kinematics Equations (2 Problems!)

For your first question, what is x? Is it displacement, velocity or what?
12. Kinematics Equations (2 Problems!)

No, depends on reference. You can say gravity has a negative acceleration in the y prime, but a falling object is accelerating. The correct term is negative acceleration, not decelerating. Note: I could be wrong.
13. Projectile Motion of launched ball

Projectile Motion - Finding The Angle Homework Statement You are standing 10 m away from a basketball net that is 14 m above the ground. Assume delta d[y] is 14 m, do not account for your height. You launch the ball with a velocity of 25 m/s and it goes in the hoop. At what angle(s)...
14. Kinetic, potential and mechanical energy question.

Ok, I did this: a) Eg = mgh Ek = mv^2, where v I put 260 m/s Et1 = Eg + Ek b) Same thing as above but with the second values. Elost = Et1 - Et2. The answer is supposed tob e 5.5 x 10^9 Joules but i get 4.98 x 10^9 Joules. What did I do wrong? Did I go about this the right way?

Thanks dude!
16. Kinetic, potential and mechanical energy question.

Homework Statement A 5.5 x 10^4 kg airplane, travelling at an altitude of 9.9 km, has a speed of 260 m/s relative to the ground. Nearing the end of the flight, the plane slows to a speed of 140 m/s while descending to an altitude of 2.1 km. Determine the plane's total loss of mechanical energy...