Aflight attendant pulls her 75.8 n flight bag a distance of 256 m along a level airport floor at a constant velocity. the force she exerts is 47.0 n at an angle of 62.4◦ above the horizontal. a) find the work she does on the flight bag. answer in units of j.

Let's start by drawing a free body diagram. We have two forces acting on a bag: pulling force and a friction force.

Pulling force is acting under some angle with respect to a ground. This means that we can find horizontal and vertical component of a force. We are only interested in horizontal component as the bag is moving over a horizontal floor.

We use this formula to find the component:


The First Newton law says "if the body is moving at a constant speed the net force acting on an object is zero". This means that horizontal component of a pulling force and a friction force are equal.

Formula for work is:


Where F is force causing the body to move, and s is a distance traveled.

This is our work.

Why did we ignore vertical component?
If we calculate it we will get the value F=41.7N. This is less than the weight of a bag and it is not enough to cause a vertical movement of a bag.