Speed of objects as they hit the ground

  • Context: Undergrad 
  • Thread starter Thread starter yrjosmiel
  • Start date Start date
  • Tags Tags
    Ground Speed
Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
3 replies · 2K views
yrjosmiel
Messages
53
Reaction score
5
Let's say there are two objects. One is thrown directly downward at v0 and the other is thrown horizontally (90 degrees) at v0, both from height h. Which object will have a higher speed by the time they hit the ground? Would they have the same speed?

For the object thrown downward...
h = (vf2 - v02)/2a
vfy axis = sqrt(v02 + 2ah)
final speed = sqrt(v02 + 2ah)

For the object thrown horizontally
vy axis = sqrt(2ah)
vx axis = v0
add the two vectors
vftotal = sqrt(v02 + 2ah)

Is this right? Or have I miscalculated something in the way?
 
Physics news on Phys.org
Looks good to me. The matching velocities speeds make sense when you consider conservation of energy.
 
Last edited by a moderator: