Force, Mass, Motion/Gravity&Frictions
What is an example of a force?
A push upward
What is gravity?
A force that pulls thing toward each other
According to Newton's first law, an object in motion will stay in motion unless:
an opposing force acts on it
What is net force?
combined forces acting on a particular object
If the net force on an object is zero, what can you conclude?
the object is not accelerating
A student pulls four classroom objects with the same amount of force. Give an example of an object's motion will the pull have the greatest effect?
desk, chair, pencil, textbook
pencil
How does the distance between objects affect the force of gravity between them?
the smaller the distance, the greater the force of gravity
What might happen if you were in a braking car, and you weren't wearing your seat belt?
You'd fly forward into the windshield
According to Newton's third law, what happens when you push against a wall?
the wall pushes back at you with the same amount of force
What can you infer about an object moving at a constant velocity?
the forces acting on it on in balance
The force that pulls objects toward each other
gravity
acts when two surfaces touch each other
What causes a ball rolling across a rug to slow to a stop?
friction resists the ball's moving forward
According to Newton, what kinds of objects are affected by gravity?
all objects in the universe
Acceleration occurs when an object is subjected to a(n):
unbalanced force
A force that acts between surfaces that touch each other.
friction
How does air resistance affect the motion of a falling object?
It reduces the object's speed
If an unbalanced force acts on an object, what will happen?
it will accelerate in the same direction as the force
What is true about all forces?
they involve more than one object
If you drop an egg off of the Empire State Building, which of the following things will happen first?
drag will increase (acts to oppose an object)
Friction between a moving object and air particles
air resistance
What will happen if you're in a car, and the driver slams on the brake?
you will continue moving forward
Ordinarily, gravity and the normal force counterbalance each other. In other words
the cancel each other out
What does the measurement unit N stand for?
newton
Which of the following statements is always true?
Unbalanced forces lead to a change in speed or direction