Science Bee: What is Force and Motion?

Are you sitting down as you read this? Are you sitting completely still? If you answered “yes” to either of those questions, you might be surprised to learn that you actually are moving, and you have the universe to thank for that. While certain objects, like your chair, for instance, might seem at rest, everything in the world is really in constant motion; all matter in this universe is packed with atoms that vibrate with energy. Matter is anything that has mass and takes up space. So, why does your chair stay still beneath you with all that atomic energy? And why does a ball move if you kick it? Over 300 years ago, physicist Sir Isaac Newton set out to answer these questions about forces and motion.

Force is the hidden strength or energy that moves an object in our universe. A force is a pushing or pulling action that can make objects move, change direction or even change shape; it allows planets to orbit the Sun and your heart to pump blood. There are six kinds of forces that act on objects when they come into contact with one another: Normal force, applied force, frictional force, tension force, spring force and resisting force. These forces make objects change their motion or movement, the act of going from one place to another.

A normal force is the support force applied to a stable object that is in contact another stable object. For example, if a book is resting on your desk, then the desk is exerting an upward force on the book in order to support the book’s weight. An applied force refers to a force applied to an object by a person or another object. If you were to push your chair across the room, then you’d be applying the force upon the chair. A frictional force occurs when two surfaces come in contact with each other, like when a driver slams on the breaks, causing their car to skid to a stop; the car tires exert a sliding friction force on the road. A tension force is the force transmitted through a string, rope, cable or wire when pulled tight by forces acting from opposite ends. This force is directed along the string and pulls equally on the objects or people at the opposite ends of the string. Spring force is created when a spring is stretched or compressed. The spring can pull or push in order to generate the force. Resisting force includes air resistance that acts upon objects as they travel through the air.

All these different types of forces relate to motion. Sir Isaac Newton linked force and motion in his three Laws of Motion that apply to almost everything in this universe. Newton’s first law states that all objects will remain at rest or in a uniform, straight motion unless compelled to change their state by the action of an external force. His second law explains that when a force pushes or pulls on an object, the force changes the object’s speed or direction, making it accelerate. He clarified that the bigger the force, the more the object accelerates. His third and final law specifies that, when a force acts on an object, there’s an equal force called a reaction acting in an opposite direction. In other words, every action has an equal and opposite reaction.

At Bayer, we use force and motion every day, from our drive to work, to the machinery we use to manufacture vital medicines. Although we always feel in motion, we like to take a second to stop and think about the essential forces powering us through all parts of our lives.

Sources:

Chris Woodford, “Forces and motion,” Explain That Stuff, https://www.explainthatstuff.com/motion.html.

“Force and Motion: Facts,” Science Trek, http://idahoptv.org/sciencetrek/topics/force_and_motion/facts.cfm.

“Types of Forces,” The Physics Classroom, http://www.physicsclassroom.com/class/newtlaws/Lesson-2/Types-of-Forces.