Projectile motion (magnitude and direction)

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Homework Help Overview

The problem involves projectile motion, specifically determining the magnitude and direction of a projectile's velocity after a certain time interval, given its initial speed and launch angle.

Discussion Character

  • Exploratory, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss calculating the vertical and horizontal components of velocity after 4 seconds, with some expressing uncertainty about the process.

Discussion Status

Some participants have provided guidance on using kinematic equations to find the final velocities, while others are still seeking clarification on the steps involved. There appears to be a productive exchange of ideas, with at least one participant indicating understanding after the discussion.

Contextual Notes

Participants are working within the constraints of a homework assignment, which may limit the amount of direct assistance they can receive.

blazeuofa
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Homework Statement


A projectile is fired at a speed of 45 m/s at an angle of 40 degrees above horizontal. Determine the magnitude and direction of its velocity 4 seconds later.


Homework Equations


ax=0 ay=-g


The Attempt at a Solution

 
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find the vy and the vx after 4 seconds and find the resultant vector.
 
needlottahelp said:
find the vy and the vx after 4 seconds and find the resultant vector.

yeah i don't get how to do that though
 
oh hahah ok well
Given: vi= 45 m/s and t = 4
so vyi = sin (40) vi and vxi = cos (40) vi

and to find the speed in four seconds you use the kinematics equation
vyf = vyi + (ay) (t) and velocity in the horizontal remains constant since ax = 0

find those to values and vf = sqrt ( vyf^2 + vxf ^2)

Do you understand it? if not I'll try to explain it a bit more
 
yeah i got it thanks
 

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