Circular Motion Plicker Review

Talk with your neighbor.. How can something be moving at a constant speed and accelerate at the same time? Must be traveling in a curved path resulting in a change of velocity (direction) but not speed.

Speed, Velocity, & Acceleration Average speed = 2πr/T Velocity scalar quantity speed + direction Acceleration = change in velocity/time

Gravitational Force Plicker Review The more massive that an object is, the ______ that the object will be attracted to Earth. A. More B. Less C. Nonsense! The the greater the earth’s radius, the ______ that the object will be attracted to Earth. More B. Less C. Nonsense! Fgrav = Gm1m2/d2 Determine the force of gravitational attraction between a 52.0 kg mother and a 3.0 kg child if their separation distance is 1 meter. What would happen to this value if the distance between them is tripled? A. Decrease by 1/3 B. Decrease by 1/9 C. Triple D. Double

Acceleration of Gravity Plicker Review True (A) or False (B) : The acceleration of gravity experienced by objects orbiting the earth depend upon the mass of the object. Remember g = Gmcentral/R2, therefore the value of g is dependent upon the mass of the central object not the orbiting object. Determine the acceleration of Pluto abour the sun if Msun=1.991x1030kg and sun-pluto distance = 5.91x1012m Doubling the distance between the an object and the earth’s center will_____ the acceleration of gravity by a factor of ____. A. Increase, 2 B. Decrease, 2 C. Increase, 4 D. Decrease, 4 g is inversely proportional to R2 or Fgrav=1/d2 False- depends upon the mass of earth

v=√(Gmcentral)/R a= Gmcentral/R2 T2/R3=(4π2)/(Gmcentral)

Satellite Motion Plicker Review True (A) or False (B) : All satellites follow circular paths. True (A) or False (B) : Satellites travel faster in their orbital paths when they are closest to earth. Where is the satellite moving fastest? Slowest? Use the following information to determine the orbital velocity and period of satellite at a location of 15000 miles above the surface of the earth. Mass Earth= 5.98 x1024kg Radius of Earth = 6.37x106m 1609m=1mile. False-elliptical orbits True- the force of gravity is greatest closest to earth resulting in a greater acceleration.

Weightlessness Plicker Review Review with your neighbor: Why do you think astronauts in space feel weightless? What is the apparent weight of a person in an upward accelerating elevator? Heavier B. Lighter C. Same When would accurate weight values be relayed 1. Heavier upward force applied to create upward acceleration & oppose gravity