# Why do some items move differently down a ramp?

## Why do some items move differently down a ramp?

Shapes – the shape of an object affects the kind of friction that has to be overcome, rolling friction is easier to overcome than sliding friction (which means round objects move easier!). Angles – the angle we place the ramp at means it is steeper or not and therefore things will move down it easier or not.

### Can a circle roll?

But if you do the same along the circumference of a circle you will have made a full rotation at the time you return to your starting point. When rolling along the same circumference, therefore, you will have made the four rolling rotations plus the one sliding revolution, for a total of five!

#### What force slows a rolling ball?

rolling friction
A ball rolling on a horizontal surface slows down as it rolls, due to rolling friction. The friction force is due to static friction so no net work is done by that force, and it does not act to dissipate energy.

What motion is involved in a homemade spinning wheel?

Instead of falling flat, the effect of gravity on the spinning wheel is a slow rotation around the string – physicists call this rotating motion of a spinning wheel precession.

How many times will a circle rotate?

Consider Circle A rolling along a straight line the length of the circumference of Circle B. Then it will revolve 3 times. It’s like the universe “knows” when to apply a different point mapping when you change the arrangement of matter.

## What makes an object roll over an area?

Any shape that contacts over an area will not roll, or it will only roll with some degree of resistance. All objects contact over an area, not a point – and all objects of the same weight contact over the same area. It’s all a matter of the forces that act on the shape and where they act.

### What kind of object will roll or slide?

Children may discover that an object such as a glue stick or pencil will roll if placed sideways, but slide if placed pointing downwards. Have children sort the objects into three groups (they will probably need to test each object again): objects that roll, objects that slide, and objects that do not move.

#### Is it true that heavier objects roll faster?

Building on our question of whether heavier objects roll faster, youth can explore verbal and mathematical definitions of velocity, acceleration, mass and time. For example, velocity (speed) is a scientific theory and is defined as the relationship between the distance an object travels and the amount of time it takes to travel in that distance.

Why does a round object keep moving around?

Since a round object has a very small common area of interaction with the other surface, it faces little friction, and hence keeps moving. Since a wide-based object has a very large common area of interaction with the other surface, it faces much friction, and hence needs more force to keep moving.