CONSTANT ACCELERATION KINEMATIC EQUATIONS - one-dimensional motion thus vector notation is not required but you still must set up a direction system - if the force of gravity is the net unbalanced force then the object is accelerating at g g = 9.81 m/s 2 [down]

-these problems are a review of grade 11 kinematics - two of the equations are quadratic equations of elapsed time and you might be required to use the quadratic formula to solve for elapsed time (one of the answers is extraneous) -when an object is thrown upwards its maximum height occurs when its velocity is zero

A ball is thrown upwards from a height of 20 m with a velocity of 20 m/s [up]. a) What height does the ball reach? b) What time does the ball reach max. height? c) How long does the ball take to reach the ground? d) What velocity does the ball hit the ground with?

20 m At maximum height v 2 is 0 For the whole flight the ball accelerates at 9.81 m/s 2 [down] The initial velocity of the ball is 20 m/s [up]

a)

b) c) d)

problems TEXT p , 24 p p.37 9, p.40 3,5-8,10 (tough) p Booklet -all of linear motion! set up half, solve half

DOUBLE OBJECT PROBLEMS -set up a direction system for each object such that each object moves in a positive direction -there will always be a link between the two objects so that one variable can be eliminated -extra information allows another equation to be written

Rowan steps from a helicopter at a height of 307 m and plummets to the earth. Mr. Moors (2 m tall) throws Rowan a football (from directly below) with a velocity 40 m/s 1 s after Rowan steps out. Assume the ball is released 2 m above the ground. At what time and height will Rowan and the football meet?

307 m 2 m

Rowanfootball

More problems on Double Object Problems sheet