Forces and Newton's Laws of Motion Flashcards
It is the interaction between two objects.
Force
It is a forces acting between objects in direct contact with each other.
Contact Forces
Properties of a Force
-A force is a push or a pull
-A force is an interaction between two objects or between an object and it’s environment
-A force is a vector quantity, with magnitude and direction
It is the force exerted by an object in contact with another object. When an object rests or pushes on a surface, the surface exerts a push on it that is directed perpendicular to the surface.
Normal Force
It is the force exerted by a surface to an object as it moves across the surface. A surface may exert a friction force on an object, directed parallel to the surface.
Friction Force
It is the force acting on an object which are tightly pulled by forces acting on the ends of an object. A pulling force exerted on an object by a rope, cord, etc.
Tension Force
It is the pull of gravity on an object is a long-range force (a force that acts over a distance)
Weight
It is any force that causes imbalance to the current state of an object’s motion whether at rest or in motion.
External Forces
Forces acting between objects that are not in direct contact with each other.
Noncontact Forces
Newton’s First Law of Motion
The Law of Inertia
It is a property of an object to resist any change in its state of motion or rest.
Inertia
It is the amount of matter present in an object.
Mass
Newton’s Second Law of Motion
The Law of Acceleration
Newton’s Third Law of Motion
Law of Interaction
It states that gravitational force is proportional to the product of the two masses and inversely proportional to the square of the distance between the point masses.
Newton’s Universal Law of Gravitation
An object at rest tends to stay at rest and an object in motion tends to stay in motion unless acted upon by an unbalanced force.
The Law of Inertia
When an object is either at rest or moving with constant velocity,
The object is in equilibrium
To be in equilibrium, the sum of forces must be
Zero
The First Law states that all objects have inertia
The more mass an object has, the more inertia it has (and the harder it is to changes it’s motion?)
Acceleration is directly proportional to the force exerted on an object and inversely proportional to the object’s mass.
The Law of Acceleration
For every action there is an equal and opposite reaction.
The Law of Interaction
Forces that do not cancel each other because they act on different objects.
Action and Reaction
Under what condition(s) will an object be in equilibrium?
A. Only if it is at rest
B. Only if it is moving with constant velocity
C. Only if it is moving with constant acceleration
D. It is either at rest or moving with a constant velocity
E. It is either moving with constant velocity or moving with a constant acceleration
D. It is either at rest or moving with a constant velocity
A small plane increases its altitude by flying with a constant velocity at an angle ° with respect to the horizontal. Which one of the following statements is true concerning the magnitude of the net force on the plane?
A. It is equal to the weight of the plane.
B. It is equal to the magnitude of the force of air resistance.
C. It is equal to zero Newtons.
D. It is less than the weight of the plane but greater than zero newtons
E. It is equal to the component of the weight of the plane in the direction of motion.
C. It is equal to zero Newtons.
A father and his seven-year-old daughter are facing each other on ice skates. With their hands, they push off against one another. Which one or more of the following statements is(are) true?
A. Each experiences an acceleration that has a different magnitude
B. Each experiences an acceleration of the same magnitude
C. Each experiences a pushing force that has a different magnitude
D. Each experiences a pushing force that has the same magnitude.
A and D
If the forces acting on an object is balanced, which statement is false?
A. The net force acting on the object is zero.
B. The forces acting on the object have the same direction.
C. The object is moving at a constant speed.
D. The object is stationary.
B. The forces acting on the object have the same direction.
Which situation below does not describe about the second law of motion?
A. Glaciers with very massive mass but changing in speed very slowly can exert a great force.
B. A bullet changing very quickly in speed can exert a great force to an object.
C. A deer running in same speed with a bull can exert greater force when it hits an object.
D. all of the above.
C. A deer running in same speed with a bull can exert greater force when it hits an object.
A net force F acts on a mass m and produces an acceleration a. What acceleration results if a net force 2F acts on mass 4m?
A. a/2
B. 8a
C. 4a
D.2a
A. a/2
Which of the following statements can be explained by Newton’s first law?
I. When your car suddenly comes to a halt, you lunge forward.
II. When your car rapidly accelerates, you are pressed backward against the seat.
A. Neither I nor II
B. Both I and II
C. I but not II
D. II but not I
B. Both I and II
The net external force acting on an object is zero. Which one of the following statements is true?
A. The object can only be stationary.
B. The object can only be traveling with a constant velocity.
C. The object can be either stationary or traveling with a constant velocity.
D. The object can only be traveling with a velocity that is changing.
C. The object can be either stationary or traveling with a constant velocity.
In which one of the following situations could an object possibly be in equilibrium?
A. Three forces act on the object; the forces all point along the same line but may have different directions.
B. Two perpendicular forces act on the object.
C. A single force acts on the object.
D. In none of the situations described in (a), (b), and (c) could the object possibly be in equilibrium.
A. Three forces act on the object; the forces all point along the same line but may have different directions.
A stone is thrown from the top of a cliff. Air resistance is negligible. As the stone falls, is it
A. in equilibrium or
B. not in equilibrium?
B. not in equilibrium?
During the final stages of descent, a sky diver with an open parachute approaches the ground with a constant velocity. There is no wind to blow him from side to side. Which one of the following statements is true?
A. The sky diver is not in equilibrium.
B. The force of gravity is the only force acting on the sky diver, so that he is in equilibrium.
C. The sky diver is in equilibrium because no forces are acting on him.
D. The sky diver is in equilibrium because two forces act on him, the downward-acting force of gravity and the upward-acting force of the parachute.
D. The sky diver is in equilibrium because two forces act on him, the downward-acting force of gravity and the upward-acting force of the parachute.
A father and his seven-year-old daughter are facing each other on ice skates. With their hands, they push off against one another. Which one or more of the following statements is (are) true?
A. Each experiences an acceleration that has a different magnitude.
B. Each experiences an acceleration of the same magnitude.
C. Each experiences a pushing force that has a different magnitude.
D. Each experiences a pushing force that has the same magnitude.
A and D
A rope is used in a tug-of-war between two teams of five people each. Both teams are equally strong, so neither team wins. An identical rope is tied to a tree, and the same ten people pull just as hard on the loose end as they did in the contest. In both cases, the people pull steadily with no jerking. Which rope sustains the greater tension,
A. the rope tied to the tree
B. the rope in the tug-of-war
C. do the ropes sustain the same tension?
A. the rope tied to the tree
