Science Force Flashcards
What is the definition of a force?
A force is a push or a pull on an object.
What can a force do to an object’s motion?
A force can change the speed, direction, or shape of an object.
Fill in the blank: To move an object, it has to be ______ or ______.
pushed; pulled
What must happen for a force to come into play?
At least two objects must interact.
True or False: A stationary object can move without the application of a force.
False.
What happens when two forces act in the same direction?
The forces add to one another.
What happens when two forces act in opposite directions?
The net force is the difference between the two forces.
What is the term used to describe the strength of a force?
Magnitude.
What happens to the speed of an object if a force is applied in the direction of its motion?
The speed of the object increases.
What happens to the speed of an object if a force is applied opposite to its motion?
The speed of the object decreases.
List the effects a force can have on an object.
- Makes an object move from rest
- Changes the speed of a moving object
- Changes the direction of motion
- Changes the shape of an object
- Causes some or all of these effects
What is muscular force?
The force resulting from the action of muscles in the body.
What is the force of friction?
The force that opposes the motion of an object.
What is a non-contact force?
A force that acts on an object without physical contact.
Give an example of a non-contact force.
- Magnetic force
- Electrostatic force
Fill in the blank: A force may cause an object to ______.
change its state of motion
What is the net force on an object if two equal forces act in opposite directions?
The net force is zero.
What happens to a ball’s motion when it strikes a ruler placed in its path?
The direction of motion of the ball changes.
What is required for an object to change shape when a force is applied?
The object must be in contact with the force.
True or False: An object can change its speed, direction, or shape by itself.
False.
What is the definition of a non-contact force?
A force that can be exerted by an object without direct physical contact with another object.
What phenomenon demonstrates that a magnet can exert force without contact?
A magnet can exert a force on another magnet without being in contact with it.
What is the electrostatic force?
The force exerted by a charged body.
What happens when a straw is rubbed with a sheet of paper?
The straw acquires an electrostatic charge.
What is gravity?
An attractive force that pulls objects towards the Earth.
What causes a coin to fall when released from a hand?
The force of gravity acting on the coin.
True or False: Gravity is a property exclusive to Earth.
False.
What is pressure?
The force acting on a unit area of a surface.
Fill in the blank: Pressure = ______.
Force/Area.
How does increasing the area of contact affect pressure when carrying heavy loads?
It reduces the pressure on the surface.
What is the relationship between area and pressure?
Smaller area results in larger pressure for the same force.
Do liquids exert pressure on the walls of their containers?
Yes.
What is atmospheric pressure?
The pressure exerted by the weight of air in the atmosphere.
What did Otto von Guericke demonstrate with his air pump?
The force of air pressure by using two hollow metallic hemispheres.
How does air pressure affect an inflated balloon?
Air inside the balloon exerts pressure in all directions.
What happens when you press a sucker against a surface?
Most air escapes, allowing atmospheric pressure to hold it in place.
What are two types of forces discussed in the text?
- Non-contact forces * Contact forces.
What is the effect of force on the state of motion of an object?
It can cause a change in speed or direction.
What does the pressure exerted by air around us indicate?
It is known as atmospheric pressure.
