Send the link below via email or IMCopy
Present to your audienceStart remote presentation
- Invited audience members will follow you as you navigate and present
- People invited to a presentation do not need a Prezi account
- This link expires 10 minutes after you close the presentation
- A maximum of 30 users can follow your presentation
- Learn more about this feature in our knowledge base article
Forces and Motion
Transcript of Forces and Motion
A force is a push or pull on an object. A force will change the motion of an object.
A push is a force that moves something away from you.
A pull is a force that moves something toward you.
Speed is how fast something is moving.
Gravity is the force that pulls all things toward the center of Earth.
The force of friction slows objects that are touching. Vocabulary A bowling ball is heavy. It takes a lot of effort to quickly roll a bowling ball down the lane. But, once the bowling ball is moving, look out! A bowling ball is also hard to stop. Bowling The bowling pins will stay still until the ball hits them. The ball must force the pins to move. A force is a push or a pull that can change an object’s motion. The size of the change is related to the size of the force. A larger force will change an object's motion more. Forces There are tools to measure force. Pulling on a scale attached to an object can measure how much force is needed to move the object. We can also measure how far an object moves to measure the amount of force on the object.
Measuring the speed of an object is also a way to measure forces. Measurement
Tools Objects Fall at the Same Rate The acceleration due to gravity is the same for all objects, no matter what their mass is. That means that all objects fall at the same rate (assuming there is no air resistance). The misconception is that a heavy object would fall faster than an object that weighed less.
Try dropping two objects at the same time, from the same height, making sure they are heavy enough not to be affected by air resistance. You will see they hit the ground at the same time. A force called friction opposes motion and can slow objects. There is friction whenever two objects rub together. For example, there is friction between the soles of your sneakers and the sidewalk. Friction keeps your shoes from slipping on the floor. Friction also causes wear. After a while, the tread on your sneakers will be gone because of friction. Friction slows down a moving car. But if there were no friction, the car would not move. The wheels would spin in one spot. Friction THE END Gravity is the force of attraction between objects. The greater the mass of each object, the greater the force of attraction. The Earth’s gravity causes all objects to fall toward the Earth. That is why a ball will roll down a ramp. The higher the ramp, the faster the ball will go. Gravity Forces and Another Big Fish Production