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Motion: Accseleration

  • #1
Vinh is investigating the bouncing ability of a golf ball and a tomato. He drops both objects from a height of 2.00m and measures the rebound heights. He found the the golf ball rebounded to 1.50m and the tomato just splattered without rebounding at all.
a) what was the speed of the golf ball jut before it hit the ground?
b) What was the speed of the tomato just before it hit the ground?
c) Calculate the speed of the golf ball ar is rebounded.
d) whitch object had the grater charge in speed as it bounced or splattered? Calculate the speed chande of this object.
e) which of these objects expireanced the greater charge in velicity as it bounced or splattered? Caculate the velocity change of this object.


The whole question I just don't get.

a) a=9.8m/s u=? x=2m t=2
x=vt+1/2at^2
2=uX2+1/2X10Xt^2
2=uX2+5Xt^2
2=uX2+5X4
2=uX2+20
u=2X2+20

u=4+20
u=24
(this answer was suppose to be 6.26m/s. I couldn't figure out how to get that number.)

I've started physics on this level with VERY little math knowledge but I want to study The Universe so I took it as my last year at high school subject.
I don't know how to do these questions very well I get confused and don't feel like making my teacher sit down every spear and going thought it with me.
 

Answers and Replies

  • #2
CWatters
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Can you do question "a" if I edit it to just this...

He drops both objects from a height of 2.00m....a) what was the speed of the golf ball jut before it hit the ground?

 
  • #3
CWatters
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a) a=9.8m/s u=? x=2m t=2
x=vt+1/2at^2
It would help if you defined your variables in plain english first

"u" is normally the initial velocity so u=0
"t" is normally time but that's not specified so where did you get t=2 from?

Are you familiar with the SUVAT equations?
 
  • #4
Yeah I am, I'm so new at this so I'm still trying to figure all of it out! Thank you for your help!!!
 
  • #5
CWatters
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Ok so question "a" askes for the final velocity (v) and gives you the distance/height (s) and the acceleration (a). You also know the initial velocity (u). Which of the SUVAT equations is most useful in that situation? I would suggest it's not one that needs time (t).
 
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