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Time of a projectile

  • Thread starter MrRandom66
  • Start date
  • #1
38
0
Problem solved, many thanks
 
Last edited:

Answers and Replies

  • #2
993
13
Write down some equations that may be used. The we can discuss which of them can apply.
 
  • #3
121
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You might want to check your units.
 
  • #4
38
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I'm really not sure what equations to use. I have a list of some equations but they ask for the initial velocity.
 
  • #5
993
13
You can find the initial speed in the vertical direction.
 
  • #6
38
0
You can find the initial speed in the vertical direction.
Could you explain that please?
 
  • #7
993
13
Try to find what is known in the vertical direction.
 
  • #8
38
0
Try to find what is known in the vertical direction.
Vertical displacement is 15m, and Gravity due to acceleration is 9.8 m s^2
 
  • #9
993
13
initial speed
final speed
distance travelled
acceleration
time
Which of the above are known in the vertical direction?
 
  • #10
993
13
What is the speed in the vertical at the maximum height?
 
  • #11
38
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Distance Travelled, and Acceleration?

Feel like I'm missing something here...
 
  • #12
993
13
Vertical displacement is 15m, and Gravity due to acceleration is 9.8 m s^2
Correct but acceleration is negative if we choose upward direction as positive.
 
  • #13
38
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Oh zero. I was missing something
 
  • #14
993
13
Now you CAN find the initial speed in the vertical direction.
 
Last edited:
  • #15
38
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Before I calculate the final speed, I have to get t, correct? So, am I write in believing this is 15m/-9.8 m s^2
 
  • #16
993
13
Before I calculate the final speed, I have to get t, correct?
I think that you mean the initial (vertical) speed.
 
  • #17
38
0
I think that you mean the initial (vertical) speed.
Yes, I did.
 
  • #18
993
13
If you know the initial and final vertical speeds, and the vertical distance you can find the time which is the quantity that you originally wanted to find.
 
  • #19
38
0
If you know the initial and final vertical speeds, and the vertical distance you can find the time which is the quantity that you originally wanted to find.
Sorry, I'm having a hard time getting my head round this.
I'm not sure what equation to use to find final velocity.
 
  • #20
993
13
You will only learn how to do physics only if you try to pick the equation yourself.
Try to find - from notes or internet - the equations you can use.
 
  • #21
38
0
OK, I've got the equation for final velocity, give me a minute and i'll work out the time.
 
  • #22
38
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Ok, so now I have the time, am I right in believe the total time for the projectile will be the time i've just calculated, x2?
 
  • #23
993
13
Yes.
 
  • #24
38
0
Brilliant! Thanks, Now i've got to work out the launch speed.... :-/

I'm going to double check my notes, but i'm sure i'll need help sooner or later.
 

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