Question

Does friction cause more energy to be wasted if the object is heavier? why?

Answer 1

Yes

Step-by-step explanation:

Let's consider an object sliding on a flat surface. In this case, the force of friction acting on the object is given by:

`F=\mu mg`

where

`\mu` is the coefficient of friction between the object and the surface

m is the mass of the object

g is the acceleration due to gravity

The work done by friction when the object slides along the surface will be therefore given by

`W=-Fd=-\mu mg d`

where

d is the displacement of the object

the negative sign is due to the fact the force of friction acts opposite to the direction of motion

So, the energy wasted due to friction is equal to

`\Delta E=-W=\mu mg d`

We see that this energy depends on the mass of the object, m. In particular, the larger the mass of the object (so, the heavier the object), the more the energy wasted. This is due to the fact that if the object is heavier, it "pushes" more against the surface on which it is sliding, and therefore, the microbumps on the surfaces which cause friction will put more "resistance" on the motion of the object, and so more energy will be wasted.