An object of mass 10 kg is pulled along a horizontal floor of a distance 3 m. The friction force between the object and the floor is 50 N. What is the minimum work done by the pulling force?
This was actually a multiple choice question. The answer given was 450J. I'm guessing, they added the weight to frictional force. But thing is, the object moved horizontally, so how could one just do this -> (100+50) x 3.
To find the minimum work done by the pulling force, we need to calculate the force exerted by the pulling force and then multiply it by the distance over which it acts.
The net force acting on the object is equal to the force exerted by the pulling force minus the friction force. This can be written as:
Net force = Pulling force - Friction force
Since the object is being pulled horizontally and at a constant velocity, the net force acting on it is zero (according to Newton's first law). Therefore, we can set up the following equation to find the magnitude of the pulling force:
Pulling force - Friction force = 0
Pulling force = Friction force
In this case, the friction force is given as 50 N. Therefore, the pulling force also needs to be 50 N to maintain a constant velocity.
Now that we know the magnitude of the pulling force, we can calculate the work done by multiplying it by the distance:
Work = Pulling force × Distance
Work = 50 N × 3 m
Work = 150 Joules
Therefore, the minimum work done by the pulling force is 150 Joules.