Physics 1 Term Test

**Momentum**

* quantity of motion that an object has
* “mass in motion”

describes an object's __resistance__ to stopping

mass and velocity

The amount of momentum that an object has is dependent upon two variable

directly proportional

momentum is ___________ to both mass and speed

**IMPULSE**

a certain amount of force you apply for a certain amount of time to cause a change in momentum.

p=mv

momentum formula

J=ft

impulse formula

**IMPULSE-MOMENTUM THEOREM**

states that the change in momentum of an object equals the impulse applied to it.

**LAW OF CONSERVATION OF MOMENTUM**

* In the __absence__ of an external force, the momentum of a system __does not__ change.

**LAW OF CONSERVATION OF MOMENTUM**

* states when a system of interacting objects is not influenced by outside forces (like friction), the total momentum of the system can not change
* the total momentum of all objects interacting with one another remains constant regardless of the nature of the forces between the objects

the total momentum of a system will stay the __same__ before and after a collision

m1v1= -m2v2

**LAW OF CONSERVATION OF MOMENTUM equation**

**RECOIL**

a term that refers to moment when a gun moves backwards after it is shot

__uniformly accelerated motion__

The motion of an object with __constant acceleration__ is also known as ___________

**COLLISIONS**

any event in which two or more bodies exert forces on each other in a relatively short time.

equals

In any collision, the total net momentum before the collision **___** the total net momentum after the collision

**ELASTIC**

When objects collide __without__ being permanently **deformed** and __without__ generating **heat**

**ELASTIC**

* Perfectly ___ collisions almost never occur
* Heat is usually generated with collisions, so energy is transformed out of the system

**ELASTIC**

* Momentum AND Kinetic energy is conserved
* No permanent deformation, no sound, no friction
* Different direction

**INELASTIC**

* When colliding objects __stick__ together and travel off as one object

Momentum is conserved, but Kinetic energy is **NOT**

**INELASTIC**

* Possible permanent deformation, sound, or friction between objects
* Work done by non-conservative forces


* Same direction

**PROJECTILE**

neglects air resistant

__**ONE-DIMENSIONAL MOTION**__

motion along a straight line or in a single direction

**MOTION**

a __change__ in position with respect to a reference point.

**DISPLACEMENT**

the __straight-line__ distance between an object’s initial and final positions, with direction toward the final position

**DISTANCE**

* the __total__ length of path taken by an object in moving from its initial to final position

**SPEED**

A __measure__ of how fast an object moves; Rate at which distance is covered; The distance traveled by a moving object per unit time

**VELOCITY**

 includes the __speed__ of an object and the direction of its motion.

**ACCELERATION**

rate of __change of velocity__; Because velocity is a vector quantity, a change in velocity can be a change in magnitude, a change in direction, or a change in both magnitude and direction

**FREE FALL MOTION**

* Objects that fall **ONLY** due to __gravity__.
* the state wherein a falling object is __free__ from air resistance and falls under the influence of gravity **alone**
* Projectile’s downward acceleration when it is on air (-9.8 m/s^2)
* Initial velocity is always 0 m/s

**PROJECTILE MOTION**

a motion in which an object is thrown near the earth’s surface, and it moves along the __curved path__ under the action of gravity only

**PROJECTILE MOTION**

Traces a curved (__parabolic__) line because at the same time that the ball is moving horizontally, it is also moving vertically under the effect of gravity.

**PROJECTILE MOTION**

Object that is initially thrown into the air and continues to move on its trajectory acted upon by gravity.

**HORIZONTAL**

one of the components of projectile motion

\
remains **constant**

entirely **independent**

**VERTICAL**

one of the components of projectile motion

\
velocity of a projectile changes

\

Time of Flight

* __Time__ taken by the projectile to cover the entire trajectory

Range

* the __horizontal__ (x) distance traveled by the projectile during entire motion

Trajectory

The parabolic __path__ followed by a projectile in air

Type I

* Horizontal, then vertical; there is an initial velocity
* a rock is thrown horizontally from the top of a cliff 88 m high, with a horizontal speed of 25m/s.

Type II

* Ground -> up -> down
* a golf ball was struck from the first tee at Lunar Golf. It was given a velocity of 50m/s at an angle of 42o to the horizontal. On the moon, the acceleration due to gravity is 1.6m/s2

Type III

* Initial velocity; 
* a diver takes off with a speed of 10 m/s from a 5 m high diving board at 30 above the horizontal.

45

best angle to fire to reach the largest distance

zero

Velocity in both highest and lowest points will always be __