New Reply

find work done given time, acceleration, and mass

 
Share Thread
Oct18-10, 10:33 AM   #1
 

find work done given time, acceleration, and mass


a box with a mass of 6.0 kg is accelerated from rest by a force across a floor at a rate of
2.2 m/s^2 for 5.9 s. Find the net work done on the box

m=6.0kg
a=2.2m/s^2
t=5.9 s
a=0 degrees

i know W=Fdcos(a)
and F=ma


so,
F=6.0kg*2.2m/s^2=13.2N
W=13.2N*d*cos0=13.2N*d

I am a little unsure as how to find d though. would it be one of the kinematic equations?
1. The problem statement, all variables and given/known data



2. Relevant equations



3. The attempt at a solution
PhysOrg.com science news on PhysOrg.com

>> Leading 3-D printer firms to merge in $403M deal (Update)
>> LA to give every student an iPad; $30M order
>> CIA faulted for choosing Amazon over IBM on cloud contract
Oct18-10, 10:44 AM   #2
 
Blog Entries: 27
Recognitions:
Gold Membership Gold Member
Homework Helper Homework Help
Science Advisor Science Advisor
hi daltomagne!

(try using the X2 icon just above the Reply box )
Quote by daltomagne View Post
a box with a mass of 6.0 kg is accelerated from rest by a force across a floor at a rate of
2.2 m/s^2 for 5.9 s. Find the net work done on the box

I am a little unsure as how to find d though. would it be one of the kinematic equations?
That's right.

You can either use one of the standard constant acceleration equations to find d, or you can use another of them to find vf, and then apply the work-energy theorem ( work done = change in mechanical energy).
Oct18-10, 11:18 AM   #3
 
so i'm thinking v=vi+at and that gives me vi=-12.98m/s
and
xf=xi+vit+1/2at2?
but that gives me a value for x=-38.3 m?

so something isn't adding up
Oct18-10, 11:26 AM   #4
 
Blog Entries: 27
Recognitions:
Gold Membership Gold Member
Homework Helper Homework Help
Science Advisor Science Advisor

find work done given time, acceleration, and mass


where's the contradiction?

one figure is speed, the other is distance, they should both give you the same work.
New Reply

Similar discussions for: find work done given time, acceleration, and mass
Thread Forum Replies
Given distance and acceleration, find time Introductory Physics Homework 7
Find Time: Constant Acceleration Introductory Physics Homework 11
Find frictional force from mass and acceleration Introductory Physics Homework 1
Using an angle and time to find Acceleration Introductory Physics Homework 6
Acceleration vs Time...Find Velocity Introductory Physics Homework 6