Calculating Projectile Motion from a Cliff: Using Coordinates and Equations

  • Thread starter Thread starter mahrouqi
  • Start date Start date
  • Tags Tags
    Ball
AI Thread Summary
To analyze the projectile motion of a ball kicked from a 20 m cliff with a horizontal speed of 10 m/s, a coordinate system is established with the origin at the cliff's edge, the x-axis directed horizontally, and the y-axis directed vertically downward. The initial vertical velocity must be calculated to ensure the ball lands after 3 seconds, leading to the determination of the vertical velocity and final speed before impact. The angle of projection relative to the horizontal can be derived from the initial velocities, and the horizontal distance traveled can be calculated using the time of flight. For the distance between the starting point and the landing point, the Pythagorean theorem is suggested as the appropriate method to find the resultant distance. The discussion emphasizes the importance of understanding the equations of motion in solving projectile problems effectively.
mahrouqi
Messages
4
Reaction score
0
From the edge of a cli of height 20 m a (heavy) ball is kicked. Neglect air resistance. The
horizontal speed is 10 m/s (directed away from the cli ). The vertical velocity is chosen
such that the ball lands on the ground below the cliff after
3 s.

First describe how you choose your coordinate system (frame of reference): origin and di-
rections of axes used; and state the equations you apply to answer the questions below.

determine
(i) the initial vertical velocity,
(ii) the velocity and the speed of the ball just before it hits the ground,
(iii) the angle  (relative to the horizontal) when it was kicked o ,
(iv) the horizontal distance between the cli and the point where the ball landed,
(v) the distance between the starting point on top of the cli and the landing point.


I solved the questions from i-iv , but i need help how can I do the v question is it by using Pythagoras theorem ? or ?


Homework Equations





The Attempt at a Solution

 
Physics news on Phys.org
Since they are seeking the distance from point A to point B, I would use Pythagorean Theorem.
 
thanks for ur answer
 
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...

Similar threads

Back
Top