Forces Homework: Finding Work and Velocity

  • Thread starter Thread starter -Physician
  • Start date Start date
  • Tags Tags
    Forces Homework
Click For Summary

Homework Help Overview

The discussion revolves around a physics problem involving a body with a mass of 1 kg subjected to a force of 5 N, resulting in a displacement of 4 m. The participants are tasked with finding the work done by the force and the final velocity of the body after the displacement, assuming no friction.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • The original poster attempts to calculate the work done using the formula Work = Force * Displacement but expresses uncertainty about finding the velocity due to the lack of time information. Some participants suggest looking for kinematic formulas that relate velocity, acceleration, and distance. Others explore the relationship between force, mass, and acceleration, leading to the use of kinematic equations to find the final velocity.

Discussion Status

The discussion is active, with participants exploring different approaches to solve for velocity. One participant successfully derives a kinematic equation to find the final velocity, which is acknowledged positively by others. There is no explicit consensus, but productive dialogue is occurring.

Contextual Notes

Participants note the absence of time as a constraint in the problem, which complicates the calculation of velocity. The original poster mentions that their teacher indicated there is a solution, suggesting that the problem may have specific parameters or assumptions that are not fully articulated in the discussion.

-Physician
Messages
85
Reaction score
0

Homework Statement


We have a body with mass=1kg and it's on rest. When a force of 5N acts on it , the body displaces 4m. Assume no friction
Find:
a)The work that force did
b)Velocity at the end of the distance(displace)
a)
##Work=Force * Displacement = 5N*4m = 20J##
##A=Fd=(5N)(4m)=20J##
b)
Uhm,
##F=\frac{mv}{t}##, i have no time given. My teacher said this has a solution, it's not wrong. I'm stuck here




The Attempt at a Solution


a)
##Work=Force * Displacement = 5N*4m = 20J##
##A=Fd=(5N)(4m)=20J##
b)
Uhm,
##F=\frac{mv}{t}##, i have no time given. My teacher said this has a solution, it's not wrong. I'm stuck here
 
Physics news on Phys.org
Look for a kinematic formula that relates velocity, acceleration, and distance, since those are the things you have to work with.
 
Ehm, maybe that would be:
##a=F/m##
##a=5N/1kg=5m/s^2##
##a=\frac{Δ v}{Δ t}##
##5m/s^2=\frac{v_1-0}{t}##
I have no v_1(which i have to find) and I have no time..
If so, would that be
##v^2=v_0^2+2ax## which gives us
##v^2=0m^2/s^2+2(5m/s^2)(4m)##
##v^2=40m^2/s^2##
##v=\sqrt{40}=6.324555320336759m/s##
 
That works!
 
thanks!
 

Similar threads

  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 58 ·
2
Replies
58
Views
3K
  • · Replies 10 ·
Replies
10
Views
3K
  • · Replies 8 ·
Replies
8
Views
1K
  • · Replies 56 ·
2
Replies
56
Views
5K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 7 ·
Replies
7
Views
1K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 1 ·
Replies
1
Views
1K