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How do I find out the angle and distance

  • Thread starter abelmoore
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  • #1
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Homework Statement


Over a completely flat surface a thermal detonator (Star Wars) is thrown by a Wookiee (a member of the rebel alliance) towards a group of imperial stormtroopers. The thermal detonator always leaves the Wookiee’s hand with a speed of 100m/s and the thermal detonator has a mass of 3.2kg.
a) Suppose that the Stormtroopers are 500m away. What is the correct angle for the Wookiee to throw the thermal detonator so that it reaches the Stormtroopers.
b) What is the maximum distance the thermal detonator could travel?
c) If we know that there is an average wind force of 0.4N in the positive horizontal direction, then redo the above calculations taking into account this added force

Homework Equations


not sure

The Attempt at a Solution


speed is 100m/s mass 3.2kg stormtroopers 500m
 
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Answers and Replies

  • #2
.Scott
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When the detonator is thrown, it will have a vertical and horizontal component.
From the vertical component, you can compute how long it will remain airborne.
In the first part of the question, the horizontal component will remain constant until the detonator lands. So if you know the time, you know the distance.

You should be able to work it out from these points.
If not, at least try to make some more progress before expecting more clues.
 
  • #3
gneill
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The Attempt at a Solution


speed is 100m/s mass 3.2kg stormtroopers 500m[/B]
This is not an attempt at solution, it's just a re-statement of the given values. You must have course notes and a textbook which covers the relevant information. There's also plenty of material on the web which you can find easily with a modicum of effort.

What type of motion is involved? What are the associated equations?
 
  • #4
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This is not an attempt at solution, it's just a re-statement of the given values. You must have course notes and a textbook which covers the relevant information. There's also plenty of material on the web which you can find easily with a modicum of effort.

What type of motion is involved? What are the associated equations?
is it linear motion https://en.wikipedia.org/wiki/Linear_motion
 
  • #5
gneill
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  • #7
gneill
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  • #8
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While it may be broadly classified as that, it's too general a description.

This is projectile motion and your text must cover this if you've been given an assignment that involves it.
what equations does that motion have
 
  • #9
gneill
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what equations does that motion have
Uh uh. We're not here to do your research for you. Do a web search on "projectile motion". Read some articles and maybe watch a few videos on the subject.
 
  • #10
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Uh uh. We're not here to do your research for you. Do a web search on "projectile motion". Read some articles and maybe watch a few videos on the subject.
are you a telephone booth
 
  • #11
gneill
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  • #12
Merlin3189
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Looking at the three questions you've posted, you must have covered linear motion with constant acceleration, motion in 2D with constant acceleration, Newtons laws and circular motion. That's quite a lot of basic kinematics, so you must be well into the course. You must have done some questions like these before and have some ideas?

Have you drawn a diagram for a start?
 
  • #13
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Looking at the three questions you've posted, you must have covered linear motion with constant acceleration, motion in 2D with constant acceleration, Newtons laws and circular motion. That's quite a lot of basic kinematics, so you must be well into the course. You must have done some questions like these before and have some ideas?

Have you drawn a diagram for a start?
i suck at physics
 
  • #14
Merlin3189
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Well maybe with a bit of encouragement you can get past that.

So what questions have you done about throwing things?
- I drop a brick off the top of a building 100 m high. How long does it take to hit the ground? How fast is it going when it hits the ground?
- You throw a ball up with a speed of 10 m/sec, how long before it comes back down? How high does it get? That sort of thing?
 
  • #15
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Well maybe with a bit of encouragement you can get past that.

So what questions have you done about throwing things?
- I drop a brick off the top of a building 100 m high. How long does it take to hit the ground? How fast is it going when it hits the ground?
- You throw a ball up with a speed of 10 m/sec, how long before it comes back down? How high does it get? That sort of thing?

first time doing these questions
 
  • #16
Merlin3189
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So what questions have you done? Nobody starts with throwing things unless they've already done some basic kinematics.
 
  • #17
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x = Vx T for the first part
 
  • #18
CWatters
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The key to understanding this type of problem is that the motion can be described by two simultaneous equations. One equation describes the horizontal motion and one equation describes the vertical motion...

The horizontal motion is at a constant velocity (so equations like distance = velocity*time can be used).
The vertical motion is constant acceleration (so the equations of motion under constant acceleration are used, see also SUVAT equations).

x = Vx T for the first part
That's ok but V is not the launch velocity. Replace V with an equation for the horizontal component of the launch velocity.
 
  • #19
haruspex
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That's ok but V is not the launch velocity. Replace V with an equation for the horizontal component of the launch velocity.
Did you mean "yes, but what is the value of Vx in terms of the angle to be found?"
 
  • #20
CWatters
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Yes. What you said. I missinterpreted Vxt as V*t.
 
  • #21
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how do I get time wait do I do vx = vcoscirclethingy is v 100 m/s
 
  • #22
haruspex
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how do I get time wait do I do vx = vcoscirclethingy is v 100 m/s
Not sure I understand that. If you mean vx=v cos(θ) where v =100m/s then yes.

Please use subscripts (X2 on the tools line), subscripts and special characters as appropriate. To get the special character palette click Σ on the tools line.
 
  • #23
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do you get time by distance/velocity
 
  • #24
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what's θ how do i get
 
  • #25
kuruman
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If this is to be treated as a projectile motion question, there is no mention of the acceleration of gravity where all this is happening. Presumably it's in a galaxy far far away.
 
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