Which of the following objects does not have more than one type of motion?

Options

A. screw
B. rolling ball
C. scooter's wheel
D. child on a seesaw

Answer

To determine which object does not have more than one type of motion, we need to analyze each option provided:

1. **Screw**:
- A screw moves in two ways: it rotates around its axis (rotatory motion) and it moves linearly as it is driven into a surface (rectilinear motion).
- Therefore, the screw has more than one type of motion.

2. **Rolling Ball**:
- A rolling ball exhibits both circular motion (as it rotates around its center) and linear motion (as it moves forward across the ground).
- Thus, the rolling ball also has more than one type of motion.

3. **Scooter's Wheel**:
- The wheel of a scooter moves in a circular motion (as it rotates) and also moves forward in a straight line (rectilinear motion).
- Hence, the scooter's wheel has more than one type of motion as well.

4. **Child on a See-Saw**:
- A child on a see-saw primarily moves up and down (which is a type of oscillatory motion). The see-saw itself pivots around a central point, but the child’s motion can be considered primarily vertical.
- Therefore, the child on a see-saw has only one predominant type of motion.

Based on this analysis, the object that does not have more than one type of motion is the **Child on a See-Saw**.

### Summary of the Solution:
- **Screw**: Rotatory + Rectilinear (more than one type)
- **Rolling Ball**: Rotatory + Rectilinear (more than one type)
- **Scooter's Wheel**: Rotatory + Rectilinear (more than one type)
- **Child on a See-Saw**: Primarily Oscillatory (only one type)

**Final Answer**: The object that does not have more than one type of motion is the **Child on a See-Saw**.