Newtons Laws Flashcards

Terms and Definitions:

1. Newtons First Law of Motion

   1. An object at rest will remain at rest unless acted on by an outside force

   2. An object in motion will remain in motion unless acted on by an outside force

      1. Ex: rolling chair, stationary chair, etc.

2. Newtons Second Law of Motion

   1. The acceleration produced by a net force is directly proportional to the magnitude of the net force

      1. Ex: F=(m)(a)

3. Newtons Third Law of Motion

   1. Whenever one body exerts a force on a second body, the second body exerts an equal and opposite force on the first

      1. Ex: Punching a wall or person

4. Force

   1. A push or pull on an object

   2. A vector quantity

   3. Required to accelerate an object

5. Free-Body Diagram

   1. A diagram showing all of the forces acting on an object

   2. All force vectors originate at the center of mass

      1. Ex: a book on a table or pushing a crate

6. Friction

   1. A constant force that opposes the motion of an object.

7. Air Resistance

   1. The frictional force air exerts against a moving object.

8. Pressure

   1. The amount of force per unit of area

9. Terminal Velocity

   1. Terminal speed together with the direction of motion

10. Action force

    1. The initial push or pull of one object on another

Questions & Knowledge

• What does “m” represent?

  • Mass

• What does “a” represent?

  • Acceleration

• What is the equation to for acceleration?

  • A = v/t or change in velocity divided by change in time

• What if there is no acceleration?

  • The velocity will remain constant

• What is the equation for weight?

  • W = (m)(g) or mass multiplied by gravity

• How is force measured?

  • In Newtons

• How is pressure measured?

  • In Pascals or (Pa)

• What is the equation for pressure?

  • P = F/a or force divided by area

• What is the equation for force?

  • F = (m)(a) or mass multiplied by acceleration

• Doubling the force on an object doubles its _____________

  • Acceleration

• All freely falling objects fall with the same acceleration because…

  • The net force on an object is only its weight, and the ratio of weight to mass is the same for all objects.

• The air resistance force an object experiences depends on…

  • The objects speed and area.

• The greater the mass…

  • The greater the terminal velocity.

• The more mass an object has the more______ there is.

  1. Inertia

1. For a constant force, an increase in the mass will __________ the acceleration.

   1. Decrease

2. Mass and Acceleration are…

   1. Inversely Proportional

3. For a constant force, an increase in the area will result in a _____________ in pressure.

   1. Decrease

4. What causes acceleration?

   1. Force

5. What happens if there are unbalanced forces action on an object?

   1. The object will accelerate.

Scenarios

1. If the force of sliding friction is 250N, what force is necessary to keep the crate sliding at constant velocity?

   1. 250N

2. If the mass of a crate is 50kg and sliding friction is 250N, what is the acceleration of the crate when pulling force is 250N, 300 N, and 500N

   1. 0m/s^2, 1m/s^2, and 5m/s^2

3. What is the net force if an object is at rest?

   1. Zero

4. What force would it take to push a 22kg mass at 2m/s^2

   1. 44N

5. What is the mass of an object that accelerates at 5m/s^2 from a force of 92N?

   1. 95/5kg

6. Superman, hearing Lois Lane yell from afar, starts from rest and accelerates to 200m/s^2 in 1.5 seconds, what is his acceleration?

   1. 200/1.3m/s^2

7. As Superman hears Lois Lane, he drops 68m/s in 4 seconds to get a better view, what is his acceleration?

   1. -17m/s^2

8. What is the weight on earth of a girl with a mass of 30kg?

   1. 300N

9. A net force of 15N is exerted on an encyclopedia to cause it to accelerate at a rate of 5m/s^2. Determine the mass of the encyclopedia.

   1. 3kg

10. A 100kg crate, sliding on the floor, is brought to a stop by a 25N force. What is the acceleration of the crate?

    1. 1/4m/s^2

11. A 40kg crate is accelerated at 8m/s^2. What is the force acting on the crate?

    1. 320N

12. Find the pressure on a table when a 750N student sits on a desk and covers 0.5m^2

    1. 1,500 Pascals

13. James Smith apples a force of 200N to a 0.5kg baseball. Find the acceleration of the ball.

    1. 400 m/s^2