AIM OF THE EXPERIMENT: To demonstrate Newton's law of action and reaction.
MATERIALS: cardboard, scissors, a ruler, a rubber band, a wide open container of water at least 10 cm deep.
MATERIALS: cardboard, scissors, a ruler, a rubber band, a wide open container of water at least 10 cm deep.
Изображение
Measure and cut a 10 x 10 cm square out of the cardboard.
With the scissors trim the square, shaping one side into a bow and cutting a 5 x 5 cm square out of the opposite side, the stern.
Cut a propeller out of the cardboard: a rectangle 2.5x5 cm.
Slip the rubber band over the stern of the boat.
Fit the propeller between the two strands of the band.
Turn the propeller towards you several times to wind the band up. Put the boat in the container of water and let the propeller go.
Now wind the band up the other way.
Put the boat in the water and let the propeller go.
RESULTS: The first time the boat goes forwards, the second time backwards.
WHY? Newton's law of action and reaction says that to every action there always corresponds a reaction directed the opposite way. We wound the band up with the propeller and then let it go, and the propeller began to unwind. As it struck the water, the propeller met the water's reaction, and the boat moved off. The boat moved the opposite way to the blade of the propeller that was under the water. When the propeller turned the other way, the boat went the other way too. METHOD:
With the scissors trim the square, shaping one side into a bow and cutting a 5 x 5 cm square out of the opposite side, the stern.
Cut a propeller out of the cardboard: a rectangle 2.5x5 cm.
Slip the rubber band over the stern of the boat.
Fit the propeller between the two strands of the band.
Turn the propeller towards you several times to wind the band up. Put the boat in the container of water and let the propeller go.
Now wind the band up the other way.
Put the boat in the water and let the propeller go.
RESULTS: The first time the boat goes forwards, the second time backwards.
WHY? Newton's law of action and reaction says that to every action there always corresponds a reaction directed the opposite way. We wound the band up with the propeller and then let it go, and the propeller began to unwind. As it struck the water, the propeller met the water's reaction, and the boat moved off. The boat moved the opposite way to the blade of the propeller that was under the water. When the propeller turned the other way, the boat went the other way too. METHOD: