What Is a Force?
What is a force?
A push or pull in a particular direction.
If forces are balanced, does motion occur?
No
What does the length of a force arrow show?
How strong the force is.
What is friction?
A force between two surfaces that rub against each other.
When you pull a window shade, you are exerting a _______.
Force.
Name three examples of forces not touching.
Gravity, magnetism, electricity.
Unbalanced forces will cause an object to ________.
Move or change motion.
What does the point of the arrow show?
he direction of the force.
Friction works ______ motion.
Against.
Which of the following would take the most force to move: A 3-pound ball,
B 5-pound ball,
C 10-pound ball, or
D 15-pound ball?
15-pound ball.
What is the unit of force?
Newton (N).
If a 10 N force pushes right and a 10 N force pushes left, what is the net force?
0 N — balanced.
What is a “net force”?
The combination of all the forces acting on an object.
Name the 4 types of friction.
Sliding, static, rolling, and fluid.
Which of the following would be easiest to move?
A 5-lb ball on grass,
B 5-lb ball on ice,
C 10-lb ball on grass, or
D 10-lb ball on ice?
5-lb ball on ice.
A force is described by its __________ and the direction it acts.
Strength.
If Zakariya pushes a desk 10 N right and Hamza pushes 15 N left, which way does the desk move?
Left
When two forces act in opposite directions,
the object moves in the direction of the _______ force.
Greater
If you want less friction, make the surface ________.
Smoother.
Which will go farthest if kicked with the same force:
A 3-pound ball,
B 5-pound ball,
C 10-pound ball, or
D 15-pound ball?
3-pound ball.
What is the full form of the unit force "Newton"?
kg x meter / second x second
or kg.m/sec2
Two students push a box from opposite sides. One pushes 20 N right, the other 15 N left.
Then, a third student pushes 5 N more to the left.
What is the total net force, and will the box move?
0 N — balanced force, no motion.
What is the net force? All working on a box
-----------------------> 7N
<-------3N
<--- 1N
---->3N
Why do car tires need friction to move forward, yet too much friction on the road can cause accidents?
Friction gives grip
If two balls of different masses roll down the same smooth ramp, which will reach the bottom first and why?
They reach at the same time because gravity accelerates all objects equally when friction is small.