8th
Invest. 7 ~Gravity~
In Gravity students learn that gravity is a universal force pulling objects to Earth with predictable acceleration.
Part 1 ~Force of Gravity~
Students are introduced to the force of gravity as an interaction between masses. They use spring scales to quantify the force due to gravity and establish the relationship between force and mass in the metric system. Students investigate falling objects to learn that they fall at the same rate.
Part 2 ~Life-Raft Drop~
Students process hypothetical data derived from a life-raft drop test to determine the acceleration due to gravity. They determine the acceleration at 10 m/s2. Students learn the equations for calculating distance and velocity when acceleration and time are known.
Part 3 ~Galileo's Discovery~
Students watch a video highlighting the life and discoveries of Galileo Galilei. They will then use Dotcars to replicate one of Galileo's experiments to see if they can confirm the rule of odd numbers. Students review their understanding of what makes things fall by revisiting the quick writes they wrote in part 1.
8th Invest. 8 ~Momentum~
In Momentum students learn to analyze collision
interactions in terms of momentum and impulse. Part 1~Crashes and Momentum~
Students investigate momentum and discover that it is proportional to mass and velocity: the greater the velocity and/or mass, the greater the momentum. They use electronic Dotcars to determine that the greater the momentum of the car, the greater the force needed to reduce its momentum to zero. Momentum applications are studied in a car-crash video.
Part 2 ~Bean Brains~
Students use information about impulse introduced in the car-crash video to engineer a device or protective environment that will allow a fragile bean brain to survive a fall or collision. They learn that the key to success is extending the time over which force is applied to the bean brain to bring its momentum to zero.
