Projectile Motion wind acceleration

Click For Summary

Homework Help Overview

The problem involves projectile motion with a pebble being accelerated by wind on a horizontal xy plane. The acceleration is given as a vector, and the initial velocity is specified. The task is to determine the magnitude and angle of the pebble's velocity after it has been displaced by a certain distance along the x-axis.

Discussion Character

  • Exploratory, Assumption checking, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the need to calculate the vertical component of velocity (Vy) and question how to derive it from the given information. There is an emphasis on the relationship between the components of velocity and the overall velocity magnitude.

Discussion Status

Participants are actively engaging with the problem, exploring the necessary calculations to find Vy and discussing the use of the Pythagorean theorem to relate the components of velocity. There is no explicit consensus yet, but guidance on using time to find Vy has been suggested.

Contextual Notes

Participants note that the initial velocity in the y-direction is zero, yet the wind's effect must be considered in the vertical direction. The discussion also hints at the need to calculate the time taken to cover the horizontal distance to find the vertical component of velocity.

soul5
Messages
63
Reaction score
0

Homework Statement


A moderate wind accelerates a pebble over a horizontal xy plane with a constant acceleration a = (6i + 7j)m/s^2 . At time t = 0, the velocity is (3i)m/s . What are the (a) magnitude and (b) angle of its velocity when it has been displaced by 12.0 m parallel to the x axis?


i= acceleration in x component , j = acceleration in y component


The Attempt at a Solution







vx^2 = (3m/s)^2 + 2 (6m/s^2) (12m/s)


vx^2= 9m/s + 144m/s

vx = 12.36


I did that and got velocity wrong what do I do?
 
Physics news on Phys.org
You're only half way home.

What's the Vy?

Just because it has no initial velocity in j doesn't mean that it isn't swept by the wind in the j direction.
 
LowlyPion said:
You're only half way home.

What's the Vy?

Just because it has no initial velocity in j doesn't mean that it isn't swept by the wind in the j direction.

So once I find Vy I use Vx^2 + Vy^2 = V^2?
 
soul5 said:
So once I find Vy I use Vx^2 + Vy^2 = V^2?

That would be the way to do it.

And tan-1(Vy/Vx) would give the angle to positive x.
 
how do I find vy?
 
Along Vx how long did it take to cover the 12m?

Use that time to determine Vy.

Vy = a*t
 

Similar threads

  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
Replies
40
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 18 ·
Replies
18
Views
2K
  • · Replies 5 ·
Replies
5
Views
3K
Replies
8
Views
3K
Replies
2
Views
2K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 14 ·
Replies
14
Views
3K