Which type of motion do the wheels of a moving car undergo?

Analysis of the Question

The question asks us to identify the specific types of motion exhibited by the wheels of a car that is moving along a straight path.

Concept Explanation

To understand this, we need to define two specific types of motion:

1. Translational Motion: This occurs when an object moves from one point to another in space. When a car moves along a road, the entire car (including its wheels) is moving forward. This forward movement is translational.
2. Rotational Motion: This occurs when an object turns about a fixed axis. As the car moves, the wheels spin around their axles. This circular, spinning movement is rotational.

When a wheel moves, it is simultaneously spinning (rotational) and moving forward with the car (translational). Therefore, the wheel undergoes both motions at the same time.

Step-by-Step Solution

1. Observe the car's movement: As the car travels down the road, the center of the wheel moves forward in a straight line. This is translational motion.
2. Observe the wheel's movement: Simultaneously, the wheel spins around its axle to allow the car to move. This is rotational motion.
3. Combine the observations: Since both motions happen concurrently, the wheels exhibit both translational and rotational motion.

Evaluating the Options

• A: Vibratory motion involves back-and-forth movement about a fixed point, which is not the primary motion of a car wheel.
• B: Random motion is erratic and unpredictable, which does not describe the controlled movement of a car wheel.
• C: Oscillatory motion is similar to vibratory motion; it is not the primary motion here.
• D: This correctly identifies the combination of moving forward (translational) and spinning (rotational).

Exam Tip

Whenever you see a question about "rolling" objects (like a ball rolling down a hill or a wheel spinning on a car), always look for the combination of Translational (moving forward) and Rotational (spinning). This is a classic JAMB physics concept!