How Is Kinetic Energy Related to Cue Ball Motion in Pool?

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Homework Help Overview

The discussion revolves around various physics problems related to work, kinetic energy, and motion, particularly in the context of a cue ball in pool, light travel from the sun, and the motion of an electron and a person walking. The subject area includes concepts from mechanics and kinematics.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the calculation of work done on a cue ball and its relation to kinetic energy. Questions are raised about the definitions of work and kinetic energy, as well as the methods to find distance given speed and time. There are attempts to clarify the equations needed for various problems, including average velocity and the relationship between speed, distance, and time.

Discussion Status

Some participants have provided calculations for specific parts of the problems, while others are seeking clarification on their approaches and the equations to use. There is an ongoing exploration of the correct methods and interpretations, with no explicit consensus reached on the solutions.

Contextual Notes

Participants express uncertainty about their calculations and the definitions of key concepts. There are indications of confusion regarding the notation used for speed and the assumptions made in the problems, particularly concerning the speed of light and the velocity of the electron.

say_uri
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Hello , i need some help solving a few questions. please help :) thankyou

a)A pool Cue exerted an average force of 160N on a cue ball over a distance of 0.012m How much work did the cue do on the ball.

b)If all the work done on (a) was transformed into kinetic energy of 0.0200kg cue ball, what was the speed of the ball?

c) Light from the sun reaches the Earth in 8.3min. The speed of light is 3.00x10g m/s. in kilometer, how far is the Earth from the sun?

d)An electron travels at a unifor velocity of 3.2x10g m/s, how much time is required for a displacement of 1.0m?

e)A person walks 5.0 km torwards the east in 2.0 hours,then 1.5 km towards the west in 0.5 hour, and finally 10.0 km torwards the east again in 2.25 hour. What is the person's average velocity?
 
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You need to show some attempt before anyone here can help you.

say_uri said:
a)A pool Cue exerted an average force of 160N on a cue ball over a distance of 0.012m How much work did the cue do on the ball.

b)If all the work done on (a) was transformed into kinetic energy of 0.0200kg cue ball, what was the speed of the ball?

What is the definition of work done and kinetic energy?

say_uri said:
c) Light from the sun reaches the Earth in 8.3min. The speed of light is 3.00x10g m/s. in kilometer, how far is the Earth from the sun?

How would you find distance given speed and time?

say_uri said:
d)An electron travels at a unifor velocity of 3.2x10g m/s, how much time is required for a displacement of 1.0m?

How do find time given distance and velocity?

say_uri said:
e)A person walks 5.0 km torwards the east in 2.0 hours,then 1.5 km towards the west in 0.5 hour, and finally 10.0 km torwards the east again in 2.25 hour. What is the person's average velocity?
What are the individual velocities for the journey?
 


well for a and b , i tried it. but i don't think it is correct.

a) w=f^d
w=160Nx0.012m
w=1.96

b) Ek=1/2mv2
i canceled , then ended up with √ 2x0.0200/1.92
V= 0.14433756729741

and for the rest of the questions i need help with the equations to use for.
c,d,and e
thanks
 


say_uri said:
b) Ek=1/2mv2
i canceled , then ended up with √ 2x0.0200/1.92
V= 0.14433756729741

You should have gotten

[tex]v = \sqrt{\frac{2E_k}{m}}[/tex]

Check it again.

For c an d, if you multiply speed and time, what do you get?
 


for c,d and e.
C) i got 2490 km
8.3x30=2490

D)320 000 3.2x100 000

E)5.0x2.0=10
1.5x0.5=0.75
10.0x2.25=22.5

i don't know what to do next?
 


for b,
i calculated again , is this one right?
0.01041666666667
 


say_uri said:
for c,d and e.
C) i got 2490 km
8.3x30=2490

D)320 000 3.2x100 000

E)5.0x2.0=10
1.5x0.5=0.75
10.0x2.25=22.5

i don't know what to do next?
What are you using for the speed of light and the speed of the electron? I don't think you mean 'g' to be 9.81 m/s2

say_uri said:
for b,
i calculated again , is this one right?
0.01041666666667

Ek is the work done in part a).
 

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