Balancing Forces
Directions
We are going to explore the idea of Balance Forces by
playing with this apple and asking a few questions
about what we observe!
When you see the white arrow, click on the apple to
continue, otherwise, click on an answer choice.
Question 1
An apple is thrown directly into the air.
What force(s) are acting on the apple
during it’s flight?
A) The force of Gravity
A) The force of your hand
C) The Force of your hand and Gravity
D) There are no forces acting on the apple
Correct!
Once the apple has left my hand, I can’t apply any
more force to it. This is because I can only use
Contact Forces. Gravity, on the other hand, is a
Field Force, and acts on the apple at all times.
Question 2
An apple is thrown into the air.
Ignoring air resistance, the forces acting
on it are…..
A) Balanced
A) Unbalanced, with the net force acting downwards
C) Unbalanced, with the net force acting upwards
D) There are no forces acting on the apple
Correct!
Ignoring the air resistance, the only force acting on
the apple is Gravity. Since gravity always pulls
towards the center of the earth, the overall force (or
Net Force) is just gravity: which will point downwards.
Question 3
An apple is resting in my hand. I can
observe that it is not changing speed or
direction. Because of this, I know…
A) The apple has no mass
A) The apple has no acceleration
C) The apple has no weight
D) There are no forces acting on the apple
Correct!
We already concluded that Gravity is always acting on
the apple, so we know that there are forces acting on
it. If we know that the speed and direction of the
apple are not changing, then it cannot have any
Acceleration.
Question 4
An apple is resting in my hand. Since I
know it is experiencing no acceleration,
and gravity acts on all objects, then…
A) The apple is experiencing unbalanced forces
B) The net force is acting downward
C) The apple is experiencing balanced forces
D) There are no forces acting on the apple
Correct!
We know that to cause an acceleration, we need to use
a force on the apple. If gravity is a force, and it is acting
on the apple, than it should be moving. Since the
apple is not moving, there must be another force
which is “canceling” or Balancing the force of Gravity.
Question 5
Since the apple has no acceleration, I
know there must be a force balancing the
pull of gravity on the apple. What is
causing this force?
A) The molecules in the air
A) The apple
C) Gravity
D) My hand
Correct!
We know that a force must be Balancing the pull of
Gravity. If I move my hand, than the apple would fall:
the balancing force disappears. If that is the case,
than my hand must be what is providing an upward
force to cancel the downward pull of Gravity.
Question 6
An apple is resting in my hand. I know
this is because my hand is balancing the
force due to gravity.
Is my hand special?
A) Yes, it is the only thing that can resist forces
A) No, any solid object will oppose forces acting on it
C) No, all hands can hold apples
D) Yes, because you are Bill Nye the Science Guy
Correct!
All solid objects resist forces upon them by applying
an opposing force in the opposite direction. This is
called a Normal force. All objects will resist with
Normal forces to balance the outside force until they
cannot resist any longer, at which point it breaks.
Thanks for Playing!
Click here
to review
again!