cq_1_082

phy 201

Your 'cq_1_08.2' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.

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A ball is tossed upward at 15 meters / second from a height of 12 meters above the ground. Assume a uniform downward acceleration of 10 m/s^2 (an approximation within 2% of the 9.8 m/s^2 acceleration of gravity).

How high does it rise and how long does it take to get to its highest point?

How fast is it then going when it hits the ground, and how long after the initial toss does it first strike the ground?

At what clock time(s) will the speed of the ball be 5 meters / second?

At what clock time(s) will the ball be 20 meters above the ground?

How high will it be at the end of the sixth second?

answer/question/discussion: ->->->->->->->->->->->-> :

acceleration = final velocity - initial velocity / time

time = 15m/10m/s= 1.5sec

maximium height = velocity * time

= 15m/s *1.5 = 22.5m

time at 5m/s = 22.5 / 5m/s = 4.5sec

time at 20m above ground = 2om/ 15m/s = 1.33sec

at the end of six second

distance = 15m/s*6sec = 90 m

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approx 15 minutes

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Good, but be sure you understand how to use positive and negative quantities to represent everything. No need to resubmit if you understand:

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Solution

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