AIM OF THE EXPERIMENT: To show how friction affects inertia.
MATERIALS: a box from a pair of women's boots, scissors, an adult helper, a ruler, ten round felt-tip pens (or pencils), a balloon (about 20 cm), a table.
MATERIALS: a box from a pair of women's boots, scissors, an adult helper, a ruler, ten round felt-tip pens (or pencils), a balloon (about 20 cm), a table.
Изображение
Ask your helper to cut a square hole in the middle of the shorter side of the box.
Put the balloon in the box so that its neck comes out through the square hole.
Blow the balloon up and pinch its neck with your fingers.
Put the felt-tip pens under the box.
Let the balloon go.
RESULTS: As the balloon deflates, the box moves forward. When all the air has left the balloon, the box travels a little further and stops.
WHY? Newton's first law states that a body will not change its state of rest or of uniform motion in a straight line until a force acts on it. This tendency to keep the previous state is called inertia. The box will stay where it stood unless it is pushed. The deflating balloon pushes the box forward. Under this force the box starts to move, and it moves until a second force opposing it — friction — gradually brings the box to a stop. Friction acts against the force that moves an object, and in the end the object stops. METHOD:
Put the balloon in the box so that its neck comes out through the square hole.
Blow the balloon up and pinch its neck with your fingers.
Put the felt-tip pens under the box.
Let the balloon go.
RESULTS: As the balloon deflates, the box moves forward. When all the air has left the balloon, the box travels a little further and stops.
WHY? Newton's first law states that a body will not change its state of rest or of uniform motion in a straight line until a force acts on it. This tendency to keep the previous state is called inertia. The box will stay where it stood unless it is pushed. The deflating balloon pushes the box forward. Under this force the box starts to move, and it moves until a second force opposing it — friction — gradually brings the box to a stop. Friction acts against the force that moves an object, and in the end the object stops. METHOD: