PHYSICS 2nd Quarter

• Projectile Motion: an object with an initial velocity and whose path is determined by the effects of gravity and air resistance
• Projectile: object being thrown or an object upon which the only force is gravity
• Projectile motion is two dimentional
• Vertical: depends on upward or downward motion of a free-falling object or force due to gravity
• Vertical Component of velocity changes with time
• Horizontal: always constant in velocity because gravity only acts downward
• The limit of the gravitational pull dictates if an object accelerates or decelerates
• True or false: Vertical components of the gravity increase because of the downward pull of gravity

  True
• the two factors which affects projectile motion are angle and initial velocity
• Upward motion has a decrease in velocity because of the gravitational pull
• horizontal: motion of a ball rolling freely along a level surface; is always constant
• Vertical: motion of a freely falling object
• Air resistance: helps the object slow down or go faster
• An Object is fired from the ground of 100 m/s of an angle of 30º.

  1. Calculate the Horizontal and vertical components of the initial velocity
  2. after 2.0 seconds, how far has the object traveled in the horizontal direction?


  • 1. 86.60m (horizontal) and 45.1m (Vertical)
  • 2. 173.21m
• Time: total time travelled using projectile motion
• Range: Horizontal component, measures distance from initial position to final
• Height: distance from x-axis to highest position
• Circular motion: motion of an object in a circular path
• Uniform circular motion: no possible without centripetal force holding it
• Centripetal force: present in an object moving in a circular path
• Centrifugal Force: not yet proved; believes that an object moves away in a circular path if not attached.
• Uniform circular motion: may have constant speed or inconsistent speed
• Period: total time traveled by the body to complete one revolution
• Radius: distance from the center tot the need of the circle
• Radical acceleration: acceleration of the body throughout
• Realtime velocity: has reference frame/point
• Dynamics: study of the causes of motion
• Forces: an example of dynamics; the reason why there is motion; push or pull of an object which causes them to move
• Classification of forces: Contact Forces and Non-Contact Forces
• Contact Forces: interaction of two objects with one another
• non-contact forces: causes motion in an object without interaction; ie. electromagnetic force
• normal force: existing on surface/flat surface; the reason why an object doesn't fall through the ground
• friction: exists in moving objects; opposite to the motion of the body
• Tension: pulling force exerted by a stretched rope on an object which it is attached to
• weight: downward gravitational force exerted by earth on an object
• Laws of inertia: An object will remain at rest or continue to move at a constant velocity unless acted upon by an outside force
• Law of Acceleration: The acceleration of an object is directly proportional to the net force acting on it.
• Law of interaction: for every action there is an equal and opposite reaction.