# Balls and Blocks

A wide choice of default balls and blocks is available, including basketballs, metal balls, bricks, and glass blocks. You can customise these by editing values such as Mass and Elasticity in the Properties pane and also add in your own images.

The Cart part is simulated as a block with no friction.

You can set up pendulums, vertical springs and other systems by linking balls or blocks to rods, springs, or strings. When dragging a rod/spring, connection pads will appear in the centres of any balls or blocks in the scene. Drag the end of a rod/spring on to a connection pad to link the ball or block to the rod/spring.

Use a ball or block with a Ground part when you want to simulate gravity.

## See also:

- Adding a velocity or force to a part
- Rods, Springs, and Strings
- Grounds
- Using motion parts