- #1

Cinnamon

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## Homework Statement

A large box containing your new computer sits on the bed of your pickup truck. You are stopped at a red light. The light turns green and you stomp on the gas and the truck accelerates. To your horror, the box starts to slide toward the back of the truck. (Assume that the truck is accelerating to the right.)

Draw clearly labeled free-body diagram for the truck. (The bed of the truck is

*not*frictionless.)

Draw the force vectors with their tails at the dot. The orientation of your vectors will be graded. The exact length of your vectors will not be graded but the relative length of one to the other will be graded.

## Homework Equations

N

_{ground}: Normal force

N

_{b}: Reaction to the normal force on the box from the truck

F

_{road}: Reaction force to tires' backward push

F

_{k}: The box's friction force on the truck bed

W

_{T}: Weight of the truck

## The Attempt at a Solution

N

_{ground}points up.

W

_{T}and N

_{b}point down.

F

_{road}points right.

F

_{k}points left.

I made the length of F

_{k}shorter than F

_{road}.

I made the length of N

_{ground}= length of W

_{T}= length of N

_{b}.

Now I'm thinking that the length of W

_{T}and N

_{b}should be equal but together add up to the length of N

_{ground}so that the net force in the y direction is 0.