Unit 4 Test Review. Define the follow vocabulary words: 1. Force: âA push or a pull exerted on an object that is measured in Newtons. 2. Newton: â...
Define the follow vocabulary words: 1. Force: A push or a pull exerted on an object that is measured in Newtons 2. Newton: The unit in which we measure force 3. Spring Scale: The tool we use to measure force
4. Acceleration: An change in the rate of speed and direction of an object 5. Balanced Force: two forces acting in opposite directions on an object, and equal in size. Anytime there is a balanced force on an object, the object stays still or continues moving continues to move at the same speed and in the same direction.
6. Unbalanced Force: Forces that cause a change in the motion of an object are unbalanced forces
7. Friction: The resistance (opposing motion) between two objects or surfaces when passing over each other or being rubbed together. A “stopping” force
8. Gravity: A natural force that causes all objects to be pulled to one another 9. Air resistance: Air resistance is the frictional force air exerts against a moving object. As an object moves, air resistance slows it down.
10. Thrust: the act of pushing or driving forward with force 11. Work: A force being exerted over a distance. Work equals force times distance (W=FxD).
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12. Joules: The unit in which work is measured
13. Give an example of an UNBALANCED FORCE and a BALANCED force. Unbalanced: Children on a see-saw, people playing tug of war, a baseball being thrown, Balanced: A golf ball sitting on a tee, a car traveling at a constant speed of 30 MPH, A student sitting in a chair
14. Explain why a ball will roll farther on a tile floor rather than a carpet floor. Tell what forces are acting upon the ball. A ball will roll farther on a tile floor rather than a carpeted floor. The ball will create more friction when rolled on the carpet than the tile. The friction will cause the ball to slow down and stop rolling. 15. Explain how mass relates to the amount of force needed to move an object. The more mass an object has the more force is needed to move the object. The less mass an object has the less force is needed to move the object. EX: A bowling ball would require more force to be thrown than a baseball 16. Using the words listed, explain the forces acting on the ball as it travels up and then down. Push, pull, friction (or air resistance), gravity. The ball is being thrown in the air by a pushing force and will ultimately fall back to Earth due to gravity. As the ball descends back to the ground its speed slows down because air resistance is being exerted against the ball. Air resistance is a frictional force.
