Find Velocity: Help on Part B | 19.6 J, 5.0 kg, 2.8 m/s

  • Thread starter Thread starter KTiaam
  • Start date Start date
  • Tags Tags
    Velocity
Click For Summary

Homework Help Overview

The discussion revolves around calculating the velocity of a mass at a specific time, given its initial velocity and the work done on it. The subject area includes concepts from mechanics, specifically relating to motion and forces.

Discussion Character

  • Mixed

Approaches and Questions Raised

  • Participants explore the relationship between force, mass, and acceleration, questioning how to derive acceleration from given work and distance. There are attempts to apply kinematic equations, but some participants express uncertainty about the necessary formulas.

Discussion Status

Some participants have provided insights into calculating acceleration and have shared their findings, while others are still working through the implications of the equations involved. There is a mix of interpretations regarding the application of formulas, but no explicit consensus has been reached.

Contextual Notes

Participants note the importance of initial conditions and the need to clarify the signs of forces involved. There is also mention of differing values for distance traveled, indicating potential discrepancies in calculations or assumptions.

KTiaam
Messages
53
Reaction score
1

Homework Statement



Given the Information in the attachment and
m = 5.0 kg

a) find how far the mass moves before stoping
b) find it's velocity at t = 5.0s

i only need help on part B

Information i found from part A
distance = 4.72 meters
work = 19.6 Joules

Homework Equations


The Attempt at a Solution



I know you need to use Vo which is 2.8 m/s but I don't know what formula to use.

I was about to use:

v = vo + at

but i have no acceleration.

please help.
 

Attachments

  • 1.JPG
    1.JPG
    6.6 KB · Views: 403
Last edited:
Physics news on Phys.org
I got a slightly different number for distance traveled.

acceleration: how about F/m? And remember signs ...
 
ah i completely forgot about

F = ma

I found Force by dividing Work over Distance

Then I used f=ma

Found a = -0.83

Then I used V = Vo + at

and got V = -1.36.

which is the answer thank you for your help

Thank you.
 
KTiaam said:
ah i completely forgot about

F = ma

I found Force by dividing Work over Distance

Then I used f=ma

Found a = -0.83

Then I used V = Vo + at

and got V = -1.36.

which is the answer thank you for your help

Thank you.

Yer' welcome. You could also have used F = 4.8cos30.

(P.S. I misread F = 4.8. You got the right answer for distance as you know by now.)
 

Similar threads

  • · Replies 10 ·
Replies
10
Views
1K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
Replies
1
Views
1K
  • · Replies 10 ·
Replies
10
Views
2K
  • · Replies 1 ·
Replies
1
Views
1K
Replies
12
Views
2K
Replies
8
Views
6K
  • · Replies 4 ·
Replies
4
Views
2K