Force, Mass, and Motion

A train travels 20 m/s​ec and takes 5 seconds to slow to 10 m/sec​. What is the train's acceleration?

• -4 m/s²

• -2 m/s²

• 2 m/s²

• 4 m/s²

Tags

NGSS.HS-PS2-1

1. Which term describes the speed and direction of an object's movement?

• Acceleration

• 1. Force

• Speed

• velocity

1. Student A and student B are pushing a box towards the right by applying force as shown. At the same time, student Y and student Z are pushing the box with the force shown, but in the opposite direction. 

Student A and student B state that the box will move in the direction of the force that they applied, while student Y and student Z state that the box will move in the direction that they applied the force.

Which Claim is valid?

• 1. The net force on the box is 7N and the box will move to the left.

• The net force on the box is 4N and the box will move to the right.

• 1. The net force on the box is 11N and the box will move in the direction of the greater force.

• 1. The net force on the box is 8N and the box will move in the direction of the lesser force.

Tags

NGSS.MS-PS2-1

NGSS.MS-PS2-2

A book is sitting on the top of a table.

Which of the following statements is correct based on Newton's Third Law?

• The weight of the book is greater than the force of the table on the book.

• The weight of the book is less than the force of the table on the book.

• The only force present is the weight of the book pushing down on the table.

• The weight of the book is exactly balanced by the force of the table.

What is gravitational force?

• 1. a measure of a body's inertia

• 1. the magnitude of the acceleration due to gravity or ​9.8 m/s2

• an attractive force between two objects that is directly proportional to their masses

• 1. an attractive force between two objects that is inversely proportional to their masses

  
  

Tags

NGSS.MS-PS2-4

Consider the following data. Based on the data, how is the rate at which an object falls influenced by its mass ​(assume air resistance is zero)?

• As the mass increases, the rate at which the object is falling increases.

• As the mass increases, the rate at which the object is falling decreases.

• As the mass increases, the rate at which the object is falling remains the same.

• As the mass increases, the rate at which the object is falling increases very slowly, but then the rate begins to increase more and more as the object nears the ground.

Tags

NGSS.MS-PS2-2

NGSS.MS-PS2-4

1. Four skydivers jump from a helicopter. Assuming that we can neglect air resistance, which diver is falling the fastest and why?

• Diver A because he has the least mass and so the force of gravity is acting greater on him.

• Diver D because he has the greatest mass and so the force of gravity is acting greater on him.

• All divers are falling at the same rate because the force of gravity is the same for each of them.

• All divers are falling at the same rate because the rate at which an object falls is independent of mass.

Tags

NGSS.MS-PS2-4

The illustration shows a class one lever, which is being used to lift an object with a weight of 8 Newtons. What is the output force of this lever?

• 1

• 2

• 4

• 8

An object of mass ​mm is falling from a building in the absence of air resistance and ​FF is the ​force of gravity. What is the relationship between the force of gravity acting on the object (​FF) and its mass (​mm)? 

• F=m/g
  

• F=g/m
  

• F = mg

• F = m²g

Tags

NGSS.MS-PS2-4

The graph depicts the displacement versus time for a car traveling on a round trip. How could the student estimate the average speed in the first 8 hours?

• use the total distance traveled for the entire trip and determine 8/20 of that total

• add the distance covered in line segment AB to BC multiplied by 8 hours

• find the distance covered in line segment AB and BC divided by 8 hours

• compute the slope of the line segment ABC divided by 8 hours