A ball is thrown straight up from ground level

AI Thread Summary
A ball is thrown straight up from ground level and reaches a height of 136.1 m after 6.1 seconds, with gravity at 9.8 m/s². The equation used to solve for initial speed is Δx = Vi*t + 1/2*a*t². Participants emphasize the need to correctly apply the equation to find the initial velocity (Vi). Clarifications are requested regarding the completion of the equation and the calculation process. The discussion focuses on ensuring the proper application of kinematic equations to solve the problem accurately.
Emely
Messages
3
Reaction score
0
A ball is thrown straight up from ground level. After a time 6.1 s, it passes a height of 136.1 m. What was its initial speed? The accelera-
tion due to gravity is 9.8 m/s2 . Answer in units of m/s.

Homework Equations

The Attempt at a Solution

 
Physics news on Phys.org
Please show your attempt at the problem (forum rules).
 
Emely said:
A ball is thrown straight up from ground level. After a time 6.1 s, it passes a height of 136.1 m. What was its initial speed? The accelera-
tion due to gravity is 9.8 m/s2 . Answer in units of m/s.

Homework Equations

The Attempt at a Solution

Delta x= 136.1
T=6.1
A=9.8
Vi*t+1/2at^2
 
CWatters said:
Please show your attempt at the problem (forum rules).
I did it
 
Emely said:
Delta x= 136.1
T=6.1
A=9.8
Vi*t+1/2at^2

That last equation is incomplete.

Vi*t+1/2at^2 = ?
 
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