Solving a Physics Problem: Net Work Done on a Box

AI Thread Summary
To solve the physics problem of net work done on a box, the initial calculations involved using the force equation f = ma, resulting in a force of 10 N. The user initially attempted to calculate work using the incorrect method of setting displacement equal to vt. Correct guidance pointed towards using the kinematic equation for constant acceleration to find displacement. After clarification, the user successfully arrived at the correct answer of 490 J for the net work done on the box. This highlights the importance of applying the right equations in physics problems.
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Homework Statement


a box of mass 5.0 kg is accelerated from rest across a floor at a rate of 2.0m/s^2 for 7.0s. find the net work done on the box.


Homework Equations


f = ma
w= fdcostheta

The Attempt at a Solution


f = ma
f=10

w = fdcostheta
w=10d
w=10*v*t
w=10*v*7
w=10*a*t*7
w = 10*14*7
w=980

the answer is 490...

need help... what am i doing wrong
 
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You set the displacement equal to vt. That is incorrect. You will need to use the correct kinematic equation for objects traveling with constant acceleration, to find the displacement.
 
thank you!

i got it!
 

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