Is Speed the Same as Magnitude of Velocity in Horizontal Projectile Motion?

  • Thread starter Thread starter MathHelpa
  • Start date Start date
  • Tags Tags
    Speed Velocity
Join the discussion
Registration is free. Start your own thread to ask a follow-up.
2 replies · 2K views
MathHelpa
Messages
4
Reaction score
0
This is a horizontal projectile problem off a building.

Is the speed of an object equal to:

##v=a*t##
or
##v = |v|## (magnitude)

Current problem:
##Velocity = √(v_0^2 + g^2(2h/g)) positive below x axis##

##t = √(2h/g)##

so is the speed suppose to be ##v = g√(2h/g) m/s##

or is it suppose to be

##|v| = √(v_o^2 + g^2(2h/g)) m/s##
 
Physics news on Phys.org
v=at is true only if the acceleration is constant and the initial velocity is zero, it is not true in your case. You can use it for one velocity component (but not the full velocity) here.

v and |v| are different objects (vector and scalar), you cannot compare them with an equal sign.

v = g√(2h/g) m/s
The "m/s" there does not make sense. The units are in g and h.

or is it suppose to be
Please post the full problem statement, if you have questions how to interpret it.
 
  • Like
Likes   Reactions: 1 person