Newton's Laws of Motion: A Concise Overview

Lab: Newton's Laws of Motion n this experiment, you will use a track, a toy car, and some washers to explore Newton's first two laws of motion. You will make observations and collect data regarding the motion of these objects. In the space below, write a general scientific question that you will answer by doing this experiment. Answer: When we run on a track or we run this car on the track, we need an external force to run the car and we again need an external force to stop that car. This verifies the law of inertia that a body do not want to change its mode. And we will also verify that the amount of force applied on the body is directly proportional to the mass of the body and its acceleration. Write a hypothesis for Part I of the lab, which is about the effect on an object being carried by a car, when the car experiences a Answer: If an object is in motion, then the object will stay in motion sudden impact. Use the format of "if . . . then . . . because . . . " and because the object has inertia be sure to answer the lesson question "How can Newton's laws be experimentally verified?" specific to Newton's first law. Write a hypothesis for Part II of the lab, which is about the relationship described by F = ma. In the lab, you will use a toy car and apply forces to it. Use the format of "if . . . then . . . because . . ." and be sure to answer the lesson question "How can Newton's laws be experimentally verified?" specific to Newton's second law. Answer: If you increase the mass m of the car, the force F will increase, while acceleration a is kept constant. Because F and m are directly proportional. If you increase the acceleration a of the car, the force F will increase, while mass m is kept constant. Because F and a are directly proportional. The variables for Part I of this experiment include whether or not the car hits the barrier and the distance that the washers travel. Use the drop-down menus to identify the independent and dependent variables. Answer: an encounter with the barrier The Distance Traveled by the washer The independent variable, the one that is intentionally manipulated, is The dependent variable, the one that you measure the response in, is From point A to point B, the car will From point B to point C, the car will Answer: Accelerate Have constant Velocity Velocity First Assuming the washer on the car is not blocked by the book, once the car hits the book, the washer will still have This experimental design will examine Newton's_______ law. The variables for Part II of this experiment include the force applied to the car and the acceleration of the car. Use the drop-down menus to complete the sentences and identify the independent and dependent variables. Answer: The Force Applied to the car The Acceleration of the car The independent variable, the one that is intentionally manipulated, is The dependent variable, the one that you measure the response in, is The normal force acting upon the car is best represented by arrow Answer: A D C The force of gravity acting upon the washers is best represented by arrow The applied force on the car is best represented by arrow The acceleration of the car with two washers added to the string would be Answer: 0.33 Which statements are part of the safety protocol for this lab experiment? Check all that apply. Answer: Always wear safety goggles when performing an experiment. Use caution when releasing the cars, being careful not add additional force. Ensure that the track has enough room and will not interfere with 1/5 others in your class. Report all accidents to the teacher. Calculate the average distances the car and the washer traveled from the top of the track. Record the average in Table A of your Student Guide. Calculate the average distances the car and the washer traveled from the top of the track. Record the averages and your qualitative observations in Table B of your Student Guide. Record what happened to the washer after the car hit the textbook. Explain whether the washer did the same thing every time. Answer: 247 cm 247 cm Answer: 75 cm 200 cm What is the average distance the car traveled? What is the average distance the washer traveled? Calculate the average times it took the car to travel 0.25 and 0.50 meters. Record the averages, to two decimal places, in Table C of your Student Guide. What is the average time it took the car to travel 0.25 meters? Answer: 2.23 seconds 3.13 seconds What is the average time it took the car to travel 0.50 meters? Calculate the average time it took the car to travel 0.25 and 0.50 meters with two washers attached to the pulley. Record the averages, to two decimal places, in Table C of your Student Guide. What is the average time it took the car to travel 0.25 meters? Answer: 1.92 seconds 2.61 seconds What is the average time it took the car to travel 0.50 meters? Calculate the average time it took the car to travel 0.25 and 0.50 meters with three washers attached to the pulley. Record the averages, rounded to two decimal places, in Table C of your Student Guide. Answer: 1.34 seconds 1.89 seconds What is the average time it took the car to travel 0.25 meters? What is the average time it took the car to travel 0.50 meters? Calculate the average time it took the car to travel 0.25 and 0.50 meters with four washers attached to the pulley. Record the averages, rounded to two decimal places, in Table C of your Student Guide. Answer: 0.88 seconds 1.33 seconds What is the average time it took the car to travel 0.25 meters? What is the average time it took the car to travel 0.50 meters? Calculate the applied force of the washers on the car. First, convert the mass you recorded for one, two, three, and four washers from grams to kilograms. Record your calculations, to four decimal places, in Table D. Calculate the gravitational force on the washers using the formula F=ma where a = 10 m/s2 and m is the mass of the washers. Use the mass of the washers in kilograms. Record your calculations, to no more than three decimal places, in Table D. Note that the force of gravity on the washers is the same as the applied force of the washers on the car. The force applied to the car by one washer is ______ kg · m/s2 The force applied to the car by two washers is ________ kg · m/s2 2/5 Answer: 0.0049 0.0098 0.0147 0.0196 Answer: 0.049 0.098 0.147 0.196 The force applied to the car by three washers is ________ kg · m/s2 The force applied to the car by four washers is ________ kg · m/s2 Calculate the first and second velocities of the car with one washer attached to the pulley, using the formulas v1=0.25 m /t1, andv2=0.25 m / (t2-t1) where t1 and t2 are the average times the car took to reach the 0.25 and the 0.50 meter marks. Record these velocities, rounded to two decimal places, in Table E. Answer: 0.11 m/s 0.28 m/s What is the first velocity of the car with one washer at the 0.25 meter mark? What is the second velocity of the car with one washer at the 0.50 meter mark? Calculate the first and second velocities of the car with two washers attached to the pulley, using the formulas v1 = 0.25 m / t1, and v2 = 0.25 m / (t2 - t1) where t1 and t2 are the average times the car took to reach the 0.25 and the 0.50 meter marks. Record these velocities, to two decimal places, in Table E. Answer: 0.13 m/s 0.36 m/s What is the first velocity of the car with two washers at the 0.25 meter mark? What is the second velocity of the car with two washers at the 0.50 meter mark? Calculate the first and second velocities of the car with three washers attached to the pulley, using the formulas v1 = 0.25 m / t1, and v2 = 0.25 m / (t2 - t1) where t1 and t2 are the average times the car took to reach the 0.25 and the 0.50 meter marks. Record these velocities, to two decimal places, in Table E. Answer: 0.19 m/s 0.45 m/s What is the first velocity of the car with three washers at the 0.25 meter mark? What is the second velocity of the car with three washers at the 0.50 meter mark? Calculate the first and second velocities of the car with four washers attached to the pulley, using the formulas v1 = 0.25 m / t1 , and v2 = 0.25 m / (t2 - t1) where t1 and t2 are the average times the car took to reach the 0.25 and the 0.50 meter marks. Record these velocities, to two decimal places, in Table E. What is the first velocity of the car with four washers at the 0.25 meter mark? What is the second velocity of the car with four washers at the 0.50 meter mark? Calculate the acceleration of the car for each set of conditions using the formula a = (v2 - v1) / (t2 - t1) where v2 and v1 are the first and second velocities and t1 and t2 are the average times the car took to reach the 0.25 and the 0.50 meter marks. Acceleration is reported in m/s2. Record these 3/5 Answer: 0.28 m/s 0.56 m/s accelerations, to two decimal places, in Table E. The acceleration for the car with one washer is _________ m/s2. The acceleration for the car with two washers is _________m/s2. The acceleration for the car with three washers is _________m/s2. Answer: 0.19 0.33 0.47 0.62 The acceleration for the car with four washers is ___________m/s2. Different measurements are expressed in different units. Choose the correct SI units for the following types of measurement. The SI units for measuring the velocity of the car: Answer: meters per second meters per second squared newtons kilograms The SI units for measuring the acceleration of the car: The SI units for measuring force: The SI units for measuring mass: What is the average velocity of the car over the first 0.25m? What is the average velocity of the car over the second 0.25m? The acceleration of the car with the data in the table above would be__________ m/s2. If the applied force were cut in half, what do you predict the acceleration would be? __________ m/s2. Answer: 0.11 m/s 0.28 Answer: 0.33 0.17 Which arrow represents the force of gravity acting upon the car? Answer: B C A Which arrow represents the normal force on the car? Which arrow represents the applied force on the car when the driver steps on the gas pedal? Use what you know about mass and how you use it to calculate force in the following situation. If each washer has a mass of 4.9 g, then the mass of two washers in kilograms would be Answer: 0.0098 kg 0.196 N Given that F = ma, and if 4 washers are attached to the string and car instead of 2, then the applied force on the car will be ________ Recall a = 10 m/s2 The average time that it takes for the car to travel the first 0.25m is ______ s. The average time to travel just between 0.25 m and 0.50 m is ________ s. Given the time taken to travel the second 0.25 m section, the velocity would be _______ m/s. Answer: 2.23 0.90 0.28 If you know the force applied to an object and measure its acceleration, which equation would you use to calculate the object's mass? Answer: m = F/a The acceleration due to gravity for any object, including 1 washer on the string, is always assumed to be ___________ m/s2 The mass of 3 washers, when converted to kg, is________ kg. 4/5 Answer: 10 0.0147 0.147 The applied force of 3 washers will increase the applied force on the car to ________ N. Consider the relationship of the variables in Newton's second law. In a drag car race, the force applied to the car is doubled by the driver stepping on the gas pedal Answer: Double Remain unchanged increase The acceleration of the car will The mass of the car will The velocity of the car will 5/5