افلام فيزياء الحركة والقوة

افلام فيزياء الحركة والقوة


Workshop 1. Making an Impact
What would happen if an asteroid were to hit the surface of the earth?
How large a crater would the impact create? In this workshop, the ideas
of force and motion are introduced, as seventh-grade students drop
balls to simulate asteroid impacts. By varying a ball’s mass, the
height from which it is dropped, or the material being struck, the
students explore what factors affect the size of the crater. They also
learn about data collection and the proper use of measurement units.
Workshop 2. Drag Races
Forces can help put objects into motion and can also bring moving
objects to a stop. In this workshop, fifth-grade students explore the
physics of motion using plastic cars with strings and washers attached
to provide a pulling force. The students test the speed of the vehicles
and explain what forces bring the vehicles to a stop, as the cars
collide with and displace barriers at the end of their run. Finally,
the students discuss their findings to help solidify their
understanding of the effect of forces on motion.
Workshop 3. When Rubber Meets the Road
A rubber band twisted around the axle of a plastic car provides the
force that moves the car forward. In this workshop, fifth-grade
students continue their exploration of force and motion by recording
and comparing the distance a vehicle travels under various conditions.
Students predict the distance the car will travel by counting the
number of twists in the rubber band, and observe the car’s speed as it
rolls across the floor. When the force of the rubber band stops acting,
the force of friction slows the car to a stop.
Workshop 4. On a Roll
The force of gravity makes a ball roll when it is placed on an incline.
In this workshop, first-grade students roll balls of different sizes,
masses, and materials down ramps of varying heights, comparing their
speeds. The students then experiment by replacing the ramp with a
cardboard tube, and try to determine how the tube must be oriented to
allow the ball to roll, much as it rolled down the ramp.
Workshop 5. Keep On Rolling
Roller coasters are filled with twists and turns, as changes in height
and direction supply a variety of push and pull forces. In this
workshop, first-grade students build on their prior experience with
rolling objects. By designing and constructing their own roller coaster
made from ramps, cardboard tubes, and flexible tubes, the students
experiment with ways to get a marble from the top of a table into a
bucket on the floor, some distance away.
Workshop 6. Force Against Force
Magnets stick to other magnets and to metal objects made of iron or
steel. How much force is required to break the attraction between two
magnets? In this workshop, fourth-grade students explore ways to
balance the force of magnetism against the force of gravity. A magnet
placed in a cup on one side of a pan-balance is stuck to a stationary
magnet beneath the cup. When enough washers are placed on the opposite
side of the balance, the magnets will separate. Graphical analysis
shows some unexpected results.
Workshop 7. The Lure of Magnetism
What is the difference between a permanent magnet and an electromagnet?
In this workshop, fourth-grade students build an electromagnet by
winding a wire around a rivet and attaching the ends to battery
terminals. The students first predict how many washers they can pick up
with the help of their electromagnet and then perform the experiment to
test their predictions. After the number of washers is recorded and the
results are discussed, the students engage in a group discussion about
practical uses for electromagnets.
Workshop 8. Bend and Stretch
We all expect a spring to stretch or compress when a force is applied,
but forces can even deform solid objects like the floor or the top of a
table. In this workshop, students in a high school classroom explore
ideas about tension and normal force. By applying a force to a spring
and measuring the distance the spring is stretched, the students
calculate the force constant or stretchiness of the spring. Lecture
demonstrations using student volunteers help to illustrate that even
rigid objects bend when a force is applied.