Question

According to Newton's universal law of gravity, everything possesses a force called gravity. The earth pulls everything toward its center due to its gravitational attraction. This is how we stay on the ground and why objects fall toward the ground.

Newton's first law of motion, called the law of inertia, states an object has a tendency to maintain its motion unless acted upon by an outside force. If an object is still, inertia keeps it still. If an object is in motion, inertia keeps it in a straight line, unless an outside force changes its course.

Newton's second law of motion states that the acceleration of an object depends on the force applied to the object and the mass of the object. Hit a baseball hard and it will fly at a faster speed than if you hit the ball softly.

Newton's third law of motion states that for every force (or action) there is an equal and opposite force (or reaction). When you hit a baseball with a bat, the baseball hits the bat with an equal but opposite force.

The experiment described below will allow you to test some of Newton's laws of gravity and motion.


Examine Newton's laws of gravity and motion in an experiment.

Water
Bucket with a handle

Fill a bucket about 3/4ths full with water.
Hold the handle of the bucket.
Swing the bucket around in a circle quickly, but at a steady speed and motion, as in the following graphic. Observe the water as you swing the bucket.
Next, slow down your swing, but at a speed and motion to keep the water in the bucket.
Observe the water at this slower speed.



Did the water stay in the bucket or did it spill out?
Was it easier to keep the water in the bucket at a faster or slower swinging speed?
What would happen to the water if you stopped the motion of the bucket while it was turned upside-down?
Describe how Newton's laws of gravity and motion relate to your observations and responses to the questions above.
Please submit your responses to the questions above in the Writer box or in an uploaded Word (.docx) document.

Answer 1

During the experiment described, the water will stay in the bucket if swung at a steady speed and motion, both when swinging quickly and when slowing down. However, if the motion of the bucket is suddenly stopped while it is turned upside-down, the water will spill out due to the force of gravity.

Newton's laws of gravity and motion can help explain these observations. The first law of motion, also known as the law of inertia, states that an object at rest will remain at rest, and an object in motion will continue moving in a straight line at a constant speed, unless acted upon by an external force. In this case, the water in the bucket tends to remain in motion due to its inertia, meaning it wants to keep moving in the same direction and speed as the bucket. This is why the water stays in the bucket when swung around in a circle.

The second law of motion states that the acceleration of an object is directly proportional to the force acting upon it and inversely proportional to its mass. When swinging the bucket at different speeds, the force acting on the water changes. At a faster swinging speed, the water experiences a greater centripetal force, pulling it towards the center of the circular motion and helping to keep it in the bucket. Therefore, it is easier to keep the water in the bucket when swinging faster.

Lastly, the third law of motion states that for every action, there is an equal and opposite reaction. When the motion of the bucket is suddenly stopped while it is turned upside-down, the force exerted on the water is abruptly reversed. This causes the water to no longer experience a centripetal force, and gravity takes over, causing the water to spill out of the bucket.

In conclusion, the observations and responses in the experiment align with Newton's laws of gravity and motion. The water's tendency to stay in motion due to inertia, the influence of centripetal force on the water's movement at different speeds, and the spilling of water when the motion abruptly stops demonstrate the application of these fundamental laws.