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Hannah1
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Calculate the speed of a proton given its kinetic energy!
Find the speed of a proton (mass = 1.67E-27 kg), if its kinetic energy is 145eV. Write your answer correct to three significant figures.
W=.5*m*v^2
Proton Mass = 1.67E-27 kg
I tried using the same method used for the problem on this link:
http://tuhsphysics.ttsd.k12.or.us/Tutorial/NewIBPS/PS17/PS17.htm#p5
145 eV = 2.32315587 × 10^-17 joules
W=.5 * m * v^2
2.32315587E-17 = .5 * 1.67E-27 * v^2
2.32315587E-17 / .5 / 1.67E-27 = v^2
v^2 = 27822225988 = 2.7822226E10
v = 166799.957998 = 1.66799957998E5 = 1.67E5
= 1.67E5 m/s
This was my answer on the homework, but I got it wrong.![Cry :cry: :cry:](/styles/physicsforums/xenforo/smilies/cry.png)
What did I do wrong??
Homework Statement
Find the speed of a proton (mass = 1.67E-27 kg), if its kinetic energy is 145eV. Write your answer correct to three significant figures.
Homework Equations
W=.5*m*v^2
Proton Mass = 1.67E-27 kg
I tried using the same method used for the problem on this link:
http://tuhsphysics.ttsd.k12.or.us/Tutorial/NewIBPS/PS17/PS17.htm#p5
The Attempt at a Solution
145 eV = 2.32315587 × 10^-17 joules
W=.5 * m * v^2
2.32315587E-17 = .5 * 1.67E-27 * v^2
2.32315587E-17 / .5 / 1.67E-27 = v^2
v^2 = 27822225988 = 2.7822226E10
v = 166799.957998 = 1.66799957998E5 = 1.67E5
= 1.67E5 m/s
This was my answer on the homework, but I got it wrong.
![Cry :cry: :cry:](/styles/physicsforums/xenforo/smilies/cry.png)
What did I do wrong??
Last edited: