UNIT II  Newton’s Laws

This assignment will allow you to demonstrate the following objectives:

  1. Illustrate the scientific method within everyday situations.

2.1 Identify the appropriate formulas necessary to solve specific scenario questions.

2.2 Calculate and analyze the acceleration and the force in various situations.

 

  1. Explain Newton’s laws of motion at work in common phenomena.

3.1 Solve problems using the law of motion.

3.2 Explore the relationship between the first and second laws.

3.3 Identify action-reaction pair in the third law.

 

 Instructions: Solve the problems below. Each question is worth 10 points. You must show your work with as much detail as possible. Answer the questions directly in this template. Before doing so, it is highly recommended that you thoroughly review the Unit II Lesson in the Study Guide.

 

  1. On a sunny spring day, Mr. Hane’s family went to a zoo in his town. His daughter looked at an elephant, and she found that the mass of the elephant is 2019 kg. What is the weight of the elephant in Newtons? Use the acceleration due to gravity (g) as 9.8 meters per second squared. (10 points)

 

  1. An apple with 0.98 N of force fell on Newton’s head while he took a rest in a garden in his hometown. What is its mass in kilograms? Use the acceleration due to gravity (g) as 9.8 meters per second squared. (10 points)

 

  1. A lunar exploration vehicle was made by a research team. The mass of the vehicle is 3,500 kg on Earth. It has an acceleration of 10 m/s2 on the moon. In order to have the same acceleration, what will be the net force acting on the vehicle on Earth? (10 points) Hint: Review Sample Question 1 in the Unit II Lesson.

 

  1. Bobby and Alice are pushing a stalled car in the same direction. The mass of the car is 2,000 kg. Bobby applies 400 N to the car while Alice applies 300 N. A force created by friction is 500 N in the opposite direction. What is the acceleration of the car? (10 points) Hint: Review Sample Question 2 in the Unit II Lesson and Example 1 on page 84 in the textbook.

 

  1. Katie pushes her boyfriend, Gabe, on an ice rink with a force of 30 N. The masses of Katie and Gabe are 60 kg and 90 kg, respectively. Calculate the acceleration of Katie and that of Gabe. (10 points) Hint: Review Sample Question 3 in the Unit II Lesson and Example 4 on page 87 in the textbook.

 

  1. Jack is hitting a punching bag to build his muscle. His left fist gains a speed of 5.5 meters per second in 0.1 seconds from rest. The mass of his left fist is 1 kg. What is the magnitude of his acceleration during 0.1 seconds? What is the average net force applied to the fist? (10 points) Hint: Review the definition of acceleration and Newton’s second law. Acceleration is defined as the change in velocity divided by the elapsed time. The net force is the product of the mass of an object and its acceleration.

 

  1. The gravity on the surface of Mars is only approximately 38% of the gravity on Earth. The gravitational acceleration on the surface of the Earth is 9.8 meters per second squared. That of Mars is 3.7 meters per second squared. What is the weight of a 100-kg object on Mars and on Earth? (10 points)

 

  1. 8. A model boat moves by the force of 500 N due north, while the wind exerts a force of 150 N due south and the water exerts a resistive force of 250 N due south. The mass of the boat is 200 kg. What is the net force between the boat, the wind, and the water? What is the magnitude of the boat’s acceleration with direction? (10 points)

 

9.Two forces of 11 N and 33 N are applied to a 22 kg box. Find (1) the box’s acceleration when both forces point due east and (2) the box’s acceleration when 11 N point due east and 33 N point due west. (10 points)

 

  1. A newly invented ride called Crazy Box in an amusement park has a strong magnet. The magnet accelerates the boxcar and its riders from zero to 35 m/s in 5 seconds. Suppose the mass of the boxcar and riders is 6,000 kg. What is the acceleration of the boxcar and its riders? What is the average net force exerted on the boxcar and riders by the magnets? (10 points) Hint: Review the definition of acceleration and Newton’s second law. Acceleration is defined as the change in velocity divided by the elapsed time. The net force is the product of the mass of an object and its acceleration.