Explain why mud guards are used on the wheels of cycles, motor cars and other driving vehicles. Give reasons why in terms of physics.

Mud guards are used to stop mud, water and gravel that becomes unstuck to the surface of the tire, flies off and travels in a straight line. The mud guard stops the flying mud from making a mess and flying rocks from causing damage to the vehicle or other vehicles. If you ride a bicycle without mud guards or fenders through a puddle you'll end up with mud on your back as it flies off...

Mud guards are used to stop mud, water and gravel that becomes unstuck to the surface of the tire, flies off and travels in a straight line. The mud guard stops the flying mud from making a mess and flying rocks from causing damage to the vehicle or other vehicles. If you ride a bicycle without mud guards or fenders through a puddle you'll end up with mud on your back as it flies off the top of the rotating back wheel.

Centripetal force is the force that makes a body follow a curved path. It's directed toward the center of the circle. When the centripetal force acting on a body is eliminated, as when the mud becomes detached from the tire, the body will cease to move in a circular path and will instead move in a straight line. Imagine that you are twirling a string with a weight attached in a circular path. If the string breaks, the weight will move in a straight line from the point where it was released, tangential to the circle its path was forming. In doing so it's following Newton's first law, an object in motion stays in motion unless acted on by a force. Mudguards provide a force to stop the debris from continuing in a straight line.