Rube Goldberg - Lab Report

At first when we were drafting the sketch, we gathered ideas from each of us and put them together. Our first idea was devising a system that makes a coffee as a final task. That idea, however, could not be accomplished due to changes in our materials and unexpected problems during making devices. When we started to set up devices and tried to connect them together, we realized that it was really different from what we had drawn on the paper. Thus, we started going step by step by setting up the first device and then thinking about the next device that was able to connect to it. Because we did not have many spaces, we had to take advantage of any space that we could on two tables. I remembered that we could not find any chemical energy transfer, so in the end we must change our final task, which is chemical energy transfer, to make it connected to the rest of the system. Through this lab, we were able to learn that we must anticipate unexpected problems and find the way to fix them.

Rube Goldberg - Post 1

When we started to build this device, we faced the tough challenge in connecting those separated devices together. Because we started drafting the sketch without knowing unexpected problems lie in the device, we failed every time we tried to connect it together. After every failure, we went back and fixed that particular place where it did not connect to the rest of the device. I can say that the toughest problem in this lab is how to connect each energy transfer together, each following the previous one.

Work and Power Lab

5.1.1: Measuring Work:

1. Because work involves the force over a distance, so the force, which is the weight of a person, depends on a person's mass. Also, work is directly proportional to force; therefore, a person weight twice as much as his friend will do twice the work.
2. If you travel along the distance from the bottom step to the top step, you are doing no work on it because you are not moving it against the force of gravity.
3. Work is the change of kinetic energy, whereas impulse is the change of momentum.
4. The work of lifting a 2000-N object a vertical distance of 10m would be equal the work of lifting a 1000-N object a vertical distance of 20m.
6. The work does not depend on time because work is defined as the product of force over a distance, which do not involve time.
7. In half revolution, the wheel travel a distance of half the circumference (pi). Work is 31.41 J.
In a complete revolution, the wheel travel a distance of 2pi(r). Work is 62.83 J.

5.1.2: Measuring Power:

1. As a person runs up the ramp in half the time of another person of equal weight, he does the same work but uses twice the power because work does not involve time while power is the work over a time period. Half of the time will cause the power to double because they have inversely proportional relationship.
2. As the vertical height of the stair is reduced by half, the work will be half of its original work. Thus, power will be reduced by half. (work and power are directly proportional).
3. It is not necessary to use greater power to perform such fears because the power indicates the work over a time period.
4. 1 hp = 745.7 Watts. The work done is (745.7W)(60s) = 44742 J. Gallons of water: 1182 gallons.
5. Power in horsepower of a 100-watt light bulb: 0.134 HP
Power in kilowatts of a 200-horsepower engine: 149.14 kW.

5.1.3: Reading Your Electric Meter:

1. 5003kWh - 3866kWh = 1137 kWh
2.

3. Because we keep consuming energy, graph of household energy consumption varies from day to day.

4. 5793kWh - 5459kWh = 334kWh. It costs $24.34.

5.1.4: Conserving Electricity

1. Unit of electric energy is kWh, while unit of electric power is W

2. I will use more energy than my friend ( 50kWh > 40kWh)

3. Power accounts for the great difference in consumption energy.

4. 1450 MW = 1450 x 10^6 W = 1450000 kW

Hooke's Law Lab

Spring

Rubber Band

1. There must be error in data because of human error like measuring the length inaccurately. Or it could be that we measured the length of the spring when it was still vibrating.
3. If you overstretch a spring or rubber band, it will cause the spring/rubber band to lose its elasticity constant. Therefore, it will affect the final result.
4. The graph force vs stretched length will give a straight line. Its slope indicates the spring constant of the spring.
5. Based on my result, the rubber band does not obey Hooke's Law because its spring constant varies too much.
6. The spring constant of the rubber band depends on the nature, the length, and the thickness of the rubber band. These will cause a difference in its spring constant.

Soda Bottle - Post Lab

• How much force is necessary to dislodge the stopper from the bottle?

The force that the stopper exerts on the bottle and the force the bottle exerts on the stopper do not cancel out. These forces act on the different object, despite that they have equal magnitude. So the force is necessary to dislodge the stopper from the bottle depends on the mass of the stopper, and perhaps mass of the bottle.


Question:

1. If one object pushes a force on another object, it will be pushed back with an equal but opposite magnitude.
2. As the gun is fired, it applies a force to launch the bullet. The bullet will push a force back to the gun, causing the gun recoils
3. The force that a ball applies to the paddle as well as the paddle applies to a ball is constant. The paddle has larger mass than the ball, so the paddle will accelerates slower than the ball. It will be hard to observe the motion of the paddle as being pushed back.

Real-world situations:

1. In launching the rocket to the space, people at NASA apply Newton's Third Law. At lift-off, hot burning gas is pushed downwards by the rocket motors. The hot gas pushes back on the rocket in an upwards direction. When this upwards push exceeds the weight of the rocket, the forces acting on the rocket are unbalanced and the rocket accelerates upwards.
2. As you are driving your car on the road. The car has to exert a force against the road. And the road has to exert the same force on your car. Otherwise, the car wouldn't be accelerating.
3. The hunter shoots the bullet from a gun. As the bullet flying out of the gun, it causes a recoil in the gun, exerting a force that pushes back the hunter. That is why he feels his body being pushed backwards. 

Soda Bottle - The Lab

Observation: As we pour the baking soda into the aluminum foil and put it inside the bottle, the bottle is filled with vinegar already. When we shake or rotate the bottle, baking soda will react with vinegar to create carbon dioxide. Carbon dioxide is created; thus, increases the pressure inside the bottle. When the bottle cannot hold enough pressure, the stopper will fly out and applies an opposite force to the bottle, causing the bottle accelerates backward.

Data:

Error analysis: Human error could be one thing to be considered. There might be errors in data as we measure the baking soda, and the vinegar. The mass of the bottle is also important because it determines the force that applying on the stopper and the bottle itself. More vinegar and baking should be used in the bigger bottle.