Vocabulary
Force that works against objects that touch as the move past each other.
Friction
What are the units for Force?
Newtons (N)
Which law is sometime referred to as the "Law of Inertia"?
First Law of Motion
Gravity depends on two things, ______ and ______.
Mass and Distance
Which type of friction is the most difficult to overcome?
Static Friction
A force is a PUSH or PULL that changes the motion of an object.
When the net force of an object is equal to _____, the force is balanced.
When the net force of an object is equal to ZERO (0), the force is balanced.
According to Newton's 2nd Law of Motion, what will happen to the acceleration if the mass of the object increases?
Acceleration would decrease
The gravity on Earth is equal to ____ m/s2.
The gravity on Earth is equal to 9.8 m/s2.
The greater the ______ of an object in motion, the harder it is to stop it.
The greater the momentum of an object in motion, the harder it is to stop it.
The constant velocity of a falling object when the force of gravity equals the force of air resistance.
Terminal Velocity
In order for an object to change motion, an ______ force must act on it.
In order for an object to change motion, an unbalanced force must act on it.
What does Newton's 3rd Law state?
Every action has an equal but opposite reaction.
When an object is falling, what force works in the opposite direction of gravity?
Air Resistance
Weight = ?
mass x gravity
Tendency of an object to resist a change in motion.
Inertia
Name the 4 main types of Friction
static friction
sliding friction
rolling friction
fluid friction
A person on a boat rows backwards, but the boat moves forward through the water. Which law of motion is this an example of?
3rd Law of Motion
Your weight would change because the moon has less gravity.
Which will have more momentum? A 40 kg person moving 2 m/s or a 2.5 kg ball moving 30 m/s?
Person -> M = 40 kg x 2 m/s = 80 N-s
Ball -> M = 2.5 kg x 30 m/s = 70 N-s
Centripetal Force
If Adam is pushing on a cart with 50 N of force to the right and Amy is pushing on the cart with 67 N of force to the left, what will be the net force on the cart? (include direction).
17N Left
The harder and ice skater pushes with his leg muscles, the faster they move on the ice.
Which law of motion is this an example of?
2nd Law of Motion
Calculate the weight of a 100 kg object here on Earth.
980 N
Two objects are at the same height. Simultaneously, Ball A is dropped vertically down; while Ball B is pushed with a horizontal velocity, resulting in it falling with projectile motion. Which ball will hit the ground first?
Both would hit the ground at the same time. This is because the only force affecting both Ball's vertical motion is gravity.