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Physics. Review. Kinematics. Kinematics. Kinematics is the study of the motion of objects without regard to the forces that produce the motion. There are six important formulas used in kinematics, four are defined and two are derived (from the defined ones).
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Physics Review Kinematics
Kinematics Kinematics is the study of the motion of objects without regardto the forces that produce the motion. There are six important formulas used in kinematics, four aredefined and two are derived (from the defined ones). Using the following six formulas, all the problems inkinematics can be solved: Defined Derived s = distance v = velocityvi = initial velocityvf = final velocity va = average velocity t = time a = acceleration Click
3.1 Kinematics Slide: Remember When calculating the average velocity of an entire trip, use the total time of the trip, even the time while not moving. Click
3.2 Find the velocity of an object after falling freely for 3 m. Click
3.3 Kinematics Slide: ti = 2 s to tf = 3 s Use g = 9.8 m/s2 if you want to be more accurate! Click
3.4 Kinematics Slide: A stone is thrown straight up with a velocity of 32 m/s towardsa tree branch that is 25 m high. With what velocity does the stone hit the branch? A) 15 m/s B) 23 m/s C) 39 m/s D) 534 m/s Click
Answer 3.5 Kinematics Slide: Click
3.6 Kinematics Slide: June dropped a stone and measured the time it took to falla certain distance. After collecting her data, she plotted theacceleration versus the time of the falling stone. Which of the following graphs represents this situation? REMEMBER Falling objects have a constant acceleration. Click
3.7 KinematicsSlide: Jack and Jill ride their bikes in an empty parking lot. The graph belowrepresents the paths of the two cyclists during a 10 second period. Note that the slope represents speed. At t = 2 s, Jack’s speed is 1 m/s but Jill’s speed is 0. Speed = 1 m/s (6/6) Speed = 0 Which of the following statements is false? A) At time t = 0, Jill is two meters ahead of Jack. B) Jill's speed is always zero. C) Between the times t=0 and t=6 s, Jack has a constant speed. D) At time t = 8 s, Jack and Jill have the same speed. E) At time t = 2 s, Jack and Jill have the same speed. Click Click
This means zeroacceleration Zero acceleration 3.8 KinematicsSlide: An automobile is traveling at a constant speed along a highway. Which set of graphs best illustrates the motion of the automobile? Constant speed Click Click
3.9 Sitting on a bench, Stefania sees a cyclist ride by in front of her traveling at constant speed in a straight line. She observed the trajectory of the reflector that is fastened to a spoke on the front wheel of the bike. Direction of bicycle Reflector Which of the following represents the trajectory that Stefania observes? Kinematics Slide: Click Click
Answer 3.10 Kinematics Slide: A ball is thrown vertically into the air with an initial velocity of 20 m/s. How high does it go? 20 m
Answer 3.11 Kinematics Slide: A ball travels horizontally with an average velocity of 35 m/s. How far does it go? 35 m 35 m 35 m 35 m 140 m
Projectiles The horizontal component of the velocityis constant (always the same) The vertical component of the velocityis the same as free fall Free fall Free fall VV = 0 V VH VV VV V VV VV V VH VV VV VH V V Height VV VV VV VV VH V VH V V VV Range The actual (or instantaneous) velocityis the vectorialsum of the horizontal and the vertical component velocities. Click
3.12 Projectiles Slide: A ball is thrown into the air with a velocity of 40 m/s at an angleof 30o. Determine its: a) Height b) Range 40 m/s Height Range
3.12 Projectiles Slide: A ball is thrown into the air with a velocity of 40 m/s at an angleof 30o. Determine its: a) Height b) Range 40 m/s
3.12 Projectiles Slide: A ball is thrown into the air with a velocity of 40 m/s at an angleof 30o. Determine its: a) Height b) Range Height 40 m/s Range 2 s going up + 2 s coming down
Quadratic equation 3.13 Projectiles Slide: Mike shoots a ball up to his friend Dave who is standing on abalcony 4.0 m high. Dave misses the ball on its way up butcatches it on its way down as illustrated below. For how may seconds was the ball in the air? NOTE For simplicity, you mayuse 10 m/s2 insteadof 9.8 m/s2 for a. Units are not shown tokeep the formula simple. If he would havecaught the ball Answer Click
The End … and good luck!