Net Force Lab 30 Points Answer the questions below. When you are finished, submit this assignment to the correct assignment folder under unit 3 for full credit. 1. The question for the lab is “How do opposing forces influence an object’s motion?” We will be applying different forces to a block of wood, which will be held in the center of a table. When we release the wood block, you will observe how the different forces cause the wood block to move. List the materials you will need to conduct this experiment below. 1 point THINK: For us to create our hypothesis, let’s review forces and what we know! (No need to answer the questions on paper, we will discuss them in class). First, what is a force? If you are applying a force to an object what direction will the object go in? What if another person is applying another force to the same object, but in a different direction? How will that change the motion of the object? PROCEDURES OVERVIEW: In this lab you will be drawing vectors to show the forces being applied to an object. The object will be a block of wood, which we will put in the center of a table. You will draw two different vectors to represent the different forces applied to the wood block. The forces will be applied by weights, which we will attach to the wood block. When creating your hypothesis for number 2, keep in mind that each weight you attach to the wood block will apply a different amount of force. 2. Let’s create a hypothesis. If you are applying two different forces to a wood block on a table, how will the wood block move? Construct your hypothesis using an “If…, then…” statement. 2 pts 3. Complete the chart to calculate the force each mass will apply to the wood block. The force is equivalent to the weight of each mass. Remember, weight is a measure of the force of gravity on an object. Weight and mass are NOT the same! 4 pts Mass (grams) 50 g 100 g 200 g 500 g Converted to kilograms (divide by 1000) Calculate Force (N) using Newton’s 2nd Law of Motion F= m (kg) x a (acceleration due to gravity = 9.8 m/s2) Select two different masses. Each weight needs to be attached to the wood block using string. You should tie the string to a weight, then tie the other end of the string to the wood block. Do this for each weight. Be sure to leave the weights on the table until you are ready to do the experiment. You will put one weight on each side of the table while your partner holds the wood block on the table. You can hang them off adjacent sides (See example pictured below) or opposite sides of the table. Next, you will release the the wood block. Pay attention to what direction the block goes in. You will repeat this three times and draw a vector diagram using the charts below to show how the block moved. Be sure to draw the net force vector of the block. Example: 1 Weight 1 – 50 N 2 Weight 2 - 100 N EXPERIMENT 1 4 Points Weight 1 - Weight 2 - EXPERIMENT 2 Weight 1 - Weight 2 - Weight 1 - Weight 2 - 4 Points EXPERIMENT 3 4 Points KEY WORDS: 3 pts Weight Net force – Vector – CONCLUSION: In your conclusion, state whether your hypothesis was supported or disproved. Provide evidence from your diagrams in your response. Discuss if it looks as if you can predict an object’s direction of motion when you know the forces acting on it? Be sure to use the vocabulary term above. Responses must be a minimum of 5 sentences (topic sentence, body/support sentences, and a conclusion) with correct grammar and punctuation, resulting in a cohesive paragraph. Use the RACES graphic organizer on the next page for help. 10 points RACES Graphic Organizer (Science Lab Conclusion) Use this graphic organizer to help map out your conclusion response. Transfer your final answer to the lab document when you finish. (Restate the hypothesis; Answer the lab question; Cite evidence from the lab; Explain how the evidence supports/disputes your hypothesis; Summarize and conclude your findings.) Type of Sentence or Sentences Letter R and A The first sentences Restate your hypothesis and Answer the question for the lab, stating whether the experiment supported, or disproved your hypothesis. This sentence is experimental support, so Cite evidence by providing qualitative (observations) or quantitative (measurements) data from the lab. C Possible sentence starters: An example of evidence that supports my answer is… The data shows… My observations demonstrate… This sentence Explains how your findings support your answer E Possible sentence starters: This evidence supports my answer because it shows… This shows… This means… These sentences are a Summary of your hypothesis, findings and explanations S Possible sentence starters: In conclusion… Overall… To summarize… Write Your Sentences in This Column
