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Forces and Motion. 2013 M.B. Pardington , BPS. A force is a…. PUSH. PULL. A force can change the motion of an object. DIRECTION. SPEED. A force can change the motion of an object. An additional force in the same direction increases the speed of the object. Push. Push + Push.
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Forces and Motion 2013 M.B. Pardington, BPS
A force is a… PUSH PULL
A force can change the motion of an object. DIRECTION SPEED
An additional force in the same direction increases the speed of the object. Push Push + Push
An additional force in the same direction increases the speed of the object. Push Push + Pull
An additional force in the same direction increases the speed of the object. Pull Pull + Pull
Opposing forces of equal magnitude acting on an object produce no change in motion. 5 N vs. 5 N Cart doesn’t move.
Opposing forces of equal magnitude acting on an object produce no change in motion. 5 N vs. 5 N Cart doesn’t move.
Opposing forces of unequal magnitude acting on an object result in a change in motion. NET FORCE 2 N PUSH to the RIGHT 3 N Pull + 5 N Push
A change in motion is described as a change in speed and/or direction of an object. NET FORCE 2 N PUSH to the RIGHT 3 N Pull + 5 N Push
BALANCED FORCE A force must be balanced in order to achieve constant speed.
UNBALANCED FORCE A force must be unbalanced (nonzero net force) in order for an object to change speed and/or direction. 20 N 40 N
UNBALANCED FORCE A force must be unbalanced (nonzero net force) in order for an object to change speed and/or direction. 20 N 30 N 50 N
UNBALANCED FORCE A change in the mass of the object will result in a change in speed and/or direction of the object. Compare these 3 carts.
UNBALANCED FORCE A change in the mass of the object will result in a change in speed and/or direction of the object. Compare these 3 carts.
UNBALANCED FORCE A change in the mass of the object will result in a change in speed and/or direction of the object. Compare these 3 carts.
Speed Speed is the ratio of distance covered per unit of time. Speed = distance / time The cart moved 6 meters per 3 seconds
Speed Mathematically, that’s 6 / 3 or 6 ÷ 3 which equals 2. The cart moved 6 meters per 3 seconds So, the cart moved 2 meters per second or 2 m/sec
FORCE NON-CONTACT CONTACT
Contact Force A contact force is a push or pull that directly touches the object..
Friction Friction is a contact force exerted between objects such as: WATER AIR OBJECTS
Non-Contact Forces MAGNETISM GRAVITY ELECTRICAL CHARGES
Non-Contact Forces These are pushes and pulls from a distance.
Gravity Gravity is a force of attraction between any mass and the matter near it. The larger the mass of an object, the greater the gravitational force it exerts on other objects. For objects on Earth, the pull of the Earth is the strongest force acting on them.
Gravity “Jupiter is the most massive planet in our Solar System and; therefore, the gravity of Jupiter is the most intense in the Solar system. Its gravitational pull is 2.5 times what is here on Earth.” http://www.universetoday.com/15110/gravity-of-jupiter/
Magnetism S S N N Here are “like” charges. Are they showing an attraction or are they repelling?
Magnetism N S S N Magnetic Repulsion They are repelling.
Magnetism N S N S Here are “unlike” charges. Are they showing an attraction or are they repelling?
Magnetism N S N S Magnetic Attraction They are showing an attraction.
Magnetism N S N S S S N N The attracting and repelling magnetic forces illustrate non-contact forces. They pull and push without contact.
Electrical Charges The attracting and repelling electrical forces illustrated in the wind sock demonstration show non-contact forces. They push without contact.
Bibliography http://powerup.ukpowernetworks.co.uk/media/22576/78.jpg http://www.clipart.dk.co.uk/DKImages/science/image_science010.jpg http://www.clipart.dk.co.uk/DKImages/science/image_science009.jpg http://www.universetoday.com/15110/gravity-of-jupiter/ http://www.mikecurtis.org.uk/images/friction.jpg http://lvp.lockyersmid.dorset.sch.uk/pluginfile.php/3230/mod_resource/content/0/content/pictures/physical/keyideas/phpkey0005.jpg http://www.united-states-flag.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/F/L/FLGBDEC1000003637_-00_st-patricks-wind-sock_4.jpg