Effect of Different Surface

Learning Outcomes

1. Students will be able to explain various factors that can affect the force of friction.
2. will be able to experience that how nature of surface affcet the friction.
3. will be able to record the observations while doing activity to show that nature of surface affects the frictional force.

Description Of Activity

How to Play

Students can be asked to come to the ground for activity. Class can be divided into five groups and asked to make friction on grass or sand, mud track or the athletic track. Another group is asked to be bare feet, having running shoes, skates or rollers. Comparative study of time and nature of surface can be taken to be tabulated by any group of students.

Table

Name of the students	Time take on grass	Time taken on mud	Time taken when wearing skates or rollers

Friction

Some examples of friction acting in sport are:

A sprinter accelerating on a track. The foot applies a force downwards and backward into the track. The friction forces of the track resist this causing forward movement (otherwise the sprinter would slip). Friction acts in the opposite direction to the force the foot applies on the track and in the same direction as the movement.

A downhill skier. As the skis glide over the snow friction forces resists the movement of the ski on the surface of the snow. These forces are much less than experienced on the track or the skier would be unable to move down the hill.

Friction is increased when:

1. One or both of the surfaces are rough.
2. The temperature of some surfaces is increased, for example, rubber tires on a racing car need to be warmed up to create more friction.

Air resistance

1. Air resistance is a friction force applied by the air on bodies that are moving through it. The amount of air resistance on a body depends on:
2. The velocity it is traveling at (the faster it goes, the more air resistance).
3. The cross-sectional area (the larger the area, the more air the body has to displace so the higher the air resistance forces).
4. The shape and surface of the body (a pointy shape is going to cut through the air more easily than a flat one and if the surfaces are smooth then the air flows over more easily).

Variations

1. Rollers/Skates/rubber skates
2. plain surface/ muddy surface
3. Shoes with spikes/ shoes with plain sole

Coaching Tips

care must be taken while doing activity as muddy surface and skates could haarm the students if they accidently fall or slip over the surface.

Equipment/Material Required

1. Muddy surface in ground.
2. Skates /rollers
3. Studded shoes