Attention Getting Question:
Did you know your body is always moving, even when you are standing still? Because the earth is always spinning on its axis, your body is always in motion.
Motion is a change in position or location of an object in relation to a nearby object or place. There are many ways to describe motion.
One way to describe motion would be to describe its path. Look at this fish swimming. You can see him swimming in a straight line, but then he turns and begins to swim in an up-and-down pattern. Watch this skier ski downhill. He is moving in a zigzag pattern down the slope.
Another way to describe motion is to use directions. You can use relative directions like left, right, forward, backward, up, and down. The red car turns left. The blue car turns right. The girl walks forward. The girl walks backward. The elevator moves down. The elevator moves up. You can also use cardinal directions. The red car moves north toward the school. The blue car moves east toward the gas station. The green car moves west toward the restaurant. The white car moves south toward the grocery store.
When you describe the motion of a car as moving fast, moving slow, turning right, or turning left, you describe its acceleration. Acceleration is the change in an object’s speed or direction. Many people only use acceleration to describe motion as speeding up, but it also means slowing down and changing directions.
Speed can also be used to measure motion. Speed is the change in position over a period of time. It can be measured in hours, minutes, or seconds. You can determine the speed by dividing the distance traveled by the amount of time it tookto travel the distance. Pretend you are starting a road trip in Minneapolis, Minnesota. You travel 235 miles northwest to Fargo, North Dakota. It takes 4 hours. If you divide 235 miles by 4 hours, you will determine that your average speed for the trip is 58.8 miles per hour.
When an object is not in motion, it will stay in its position unless a force sets it in motion. A force can also change its motion. Force is a push or pull. When you pull up weeds from your garden, you use force. When you push a heavy box across a room, you also use force.
Let’s look at this toy car. A force is added when the car is pushed to make it move. It is accelerating because it is slowing down. The path of the car is a straight line. We can measure the speed of the car as it goes down this ramp. If the car travels a length of 3 feet in a total of 6 seconds, then we can calculate the speed as 0.5 feet per second. We can continue to add force by pushing the car in a curvy path by moving the car left and right.
Examples of motion and force are all around us. Motion is the change in position or location of an object in relation to a nearby object or place and force is a push or pull. Motion can be described by using direction. Acceleration is the change in an object’s speed or direction. The speed of motion can be measured by dividing the distance traveled by the amount of time it took to travel the distance.