Free-Fall Motion (Mapped Solution)

Posted August 2nd, 2011. Filed under Guides Kinematics Physics

There are many techniques to use to solve physics problems. One of my favorites is drawing flow-chart-like diagrams showing paths to solutions.  The resulting “maps” are great visual summaries of the mental thought processes that went into solving the problems. Below is an example. At first glance it may seem overwhelming and confusing. Take some time to process the map and perhaps you will find new insight into the logical steps taken to solve the problem. See if you can apply the technique yourself to a different problem. This particular problem is a vertical free-fall problem. See if you can generalize the technique to a different type of physics problem (not kinematics). But perhaps, after taking the time to process the map, you will gain new insight into the logical steps taken to solve the problem.

A physics student throws an egg vertically upward from the edge of Byrd Science Center with an initial velocity of 10 m/s. It travels straight up, then falls straight down, and finally smashes on the ground. When the egg leaves the student’s hand, it is 15 m above the ground below. Ignoring air drag, how long did it take the egg to hit the ground, what was its velocity the instant before hitting the ground, and what is the total distance it traveled?

Note that I have broken the problem up into two parts, the part where the egg is going up (t0 to t1) and the part where the egg is falling down (t1 to t2). Click on the image to see a larger version or to download it.

From Map a Solution – Kinematics – Free Fall

Projectile Motion (Video)

Posted August 2nd, 2011. Filed under Guides Infographics Kinematics Physics

In this guided practice, I work through a projectile motion problem involving the level horizontal flight of a water balloon. I end up deriving an expression relating the range, launch angle, and initial speed of a projectile undergoing level horizontal flight. Level horizontal flight is the situation where a projectile takes off and lands at the same vertical height. The video is broken into two parts due to YouTube’s 15 minute limit on video length.

Free-Fall Motion (Video)

Posted July 31st, 2011. Filed under Guides Kinematics Physics