Projectile motion vector problem

AI Thread Summary
To determine the compensatory angle for the drone to hit a target 400m due east while accounting for a 5 m/s south wind, the problem requires analyzing the drone's velocity components. The horizontal motion is unaffected by the wind, while the vertical motion is influenced by gravity at 9.8 m/s². The discussion emphasizes the importance of correctly defining the x (east-west) and y (north-south) axes and using vector arithmetic and trigonometry for the solution. A diagram may help visualize the trajectory and forces involved. The key takeaway is to approach the problem with a clear understanding of the vectors and forces acting on the drone.
velocityay
Messages
5
Reaction score
0

Homework Statement


At what compensatory angle north of east should a drone, that can only move forward at a maximum speed of 20 m/s, be launched if it is to strike a target that is 400m due east if there is a wind moving 5 m/s south?

Homework Equations


vx=20cos\Theta
vy=20sin\Theta
vf2=vi2+2ad (I think?)

The Attempt at a Solution


I'm not sure how to start trying to solve this, I drew a small diagram labeled with north south east and west and it shows the object's trajectory over the 400 m. I set up a chart of known and unknown variables
x
d=400 m
a=0 m/s2
t= ?
vi=20cos\Theta
vf=20cos\Theta
vavg=20cos\Theta

y
d=?
a=9.8 m/s2
t=?
vi=20sin\Theta
vf=?
vavg=?that's all I can get
 
Physics news on Phys.org
First define your variables. What is x and what is y? Why is acceleration in the y direction 9.8 m/s^2?
 
x is motion on the axis from west to east and y is motion on the axis from south to north, the acceleration in the y direction is that because the only force acting on it is the gravitational force
 
Gravity doesn't work from north to south.

EDIT: My point is, you're approaching the problem from completely the wrong angle. It's simple vector arithmetic and trigonometry. Try re-drawing the problem with that in mind, and let us know how you do.
 
Last edited:
Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...

Similar threads

Back
Top