Why Is Initial Velocity Equal to Final Velocity in Parabolic Motion?

AI Thread Summary
In parabolic motion, when an object is launched and lands at the same height, its initial and final velocities are equal due to the symmetry of the trajectory. The object experiences constant gravitational acceleration of approximately 9.8 m/s² throughout its flight, affecting both the upward and downward motion equally. This symmetry means that the speed at which it is launched will match the speed at which it impacts the ground. The angle of launch also plays a role in determining the trajectory but does not affect the equality of initial and final velocities. Thus, the principles of physics governing projectile motion confirm that initial velocity equals final velocity in this scenario.
lilstar
Messages
8
Reaction score
0

Homework Statement


I was wondering, when an object's motion is in the shape of a parabola, and it lands at the same height that it was shot from.. why would the initial velocity and the angle from the ground at which it was shot from.. be equal to the final velocity at which it hit the ground?


Homework Equations





The Attempt at a Solution



Would it be because of its parabolic shape?
 
Physics news on Phys.org
Because both when moving upwards and downwards the same gravitational force is working on the object. It's acceleration is always ~9.8 m/s^{2} and directed to Earth's center.
 
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