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Movement in x,y line

  • Thread starter Gliese123
  • Start date
  • #1
144
0

Homework Statement


From a height 40 meters up, one throw a ball with the velocity of 20 m/s. The elevation is 0°. How far does the ball come?

vo = 20 m/s
x = 40 meters
α = 0°
(g=9.82)


Homework Equations



y = v0 × t × sinα - (9.82×t2)/2

x= v0×t×cosα



The Attempt at a Solution


I put what I know in there

40 = 20×t×sin0° - (9.82×t2)/2
=>
80/9.82 = t2
=>
√(80/9.82) = t = 2.85 s (Is that right?)

Then I put all I know in the other formula to get x:
x= v0×t×cosα

x = 20×2.85×cos0°
x=57 meters
(Doesn't that feel a little too short?)

I've no answer to this question and I would be really glad if someone could confirm that this is correct calculated :)
Edit: There's no air resistance
 

Answers and Replies

  • #2
Doc Al
Mentor
44,866
1,112
Looks good to me.
 
  • #3
144
0
Looks good to me.
I hope so. Thanks for checkin' it :)
 

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