Physics S1 Final Exam Review

Physics Final Exam Review S1

Quantities that have a MAGNITUDE & DIRECTION.
ex. acceleration, displacement, velocity, momentum, force

Vector

Quantities that have a MAGNITUDE ONLY!
ex. speed, distance, time, temperature

Scalar

Scalar vs. Vector Quantities

Slope is acceleration (m/s/s)





Constant Constant
Acceleration Speed

​Velocity-Time Graph

Slope is velocity (m/s)

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Constant Not
Velocity Moving

​Position-Time Graph

Position & Velocity-Time Graphs

1D Motion--movement on one place either x or y axis, but NOT both

a=(v_i-v_f)/t
a=accleration (m/s/s)
v_i=initial velocity (m/s)
v_f=final velocity (m/s)
t=time

​Acceleration Equation

v = d/t
v=velocity (m/s)
d=distance/displacement (m)
t=time (s)

​Velocity Equation

Free Fall & Projectile Motion

​Important reminders

• Gravity is ALWAYS -9.8m/s/s (downward). We often use 10 m/s/s to make the calculations easier. Remember that the negative sign indicates the direction of DOWN.

• When air resistance is not a factor, materials with different masses will land on the ground at the SAME time.

​Important Reminders about 2D motion

• 2D motion is motion in both x AND y directions.

• X and Y components are INDEPENDENT of each other!

• Horizontal velocity--is CONSTANT

• Vertical velocity--changes as it is affected by gravity (decreases as it approaches top of parabola, and decreases as it moves away from the top)

• Vertical acceleration--is CONSTANT (-9.8 m/s/s or -10 m/s/s)

• Horizontal acceleration--DOES NOT EXIST without an outside force

d_x = v_xt
d_x=range (m)
v_x=horizontal velocity (m/s)
t=time (s)

​Horizontal Motion

d_y = 1/2gt²
dy=height (m)
g=gravity (10 m/s/s or 9.8 m/s/s)
t=time (s)

​Vertical Motion

2D Motion Equations---TIME IS THE ONLY variable that is the same in both directions!

Newton's Laws

• 1st law: Objects at rest will stay at rest and objects in motion will move at a constant velocity when there is no next force.

• 2nd law: the greater the mass the more force is needed to accelerate it. (F=ma F=force (N), m=mass (kg) & a=acceleration (m/s/s) or F_w=mg; F=force (N), m=mass (kg) & g=gravity (m/s/s)).

• 3rd law: Every action force there is an reaction force that is equal and in opposite directions.

F_g=Gm₁m₂/d²
Fg = universal gravitation force
G=universal gravitation constant
m₁=mass of 1st object (kg)
m₂=mass of 2nd object (kg)
d=distance between objects (m)

**Remember to use the power of 1s

​Universal Gravitation

a_c = v²/r
a_c=centripetal acceleration (m/s/s)
v=velocity (m/s)
r=radius (m)

circular motion equation

Circular motion & universal gravitation

​Momentum, Collisions & Impulse

P=mv
I=Ft
I=p_f-p_i=Δp
I=m(v_i-v_f)=mΔv
Ft = mΔv
m₁v₁ + m₂v₂ = m₁v₁ +m₂v₂
m₁v₁ + m₂v₂ = (m₁+m₂)v_f

• p=momentum (kg*m/s)

• I=impulse (N*s)

• F=Force (N)

• t=time (s)

• v=velocity (m/s)

• vi=initial velocity (m/s)

• v_f=final velocity (m/s)

• m=mass (kg)

​Key reminders about momentum

• Momentum is a VECTOR quantity and requires a direction.

• Momentum is conserved in a closed system

• The purpose of an AIR BAG is to INCREASE the time of impact!

• 2 types of collisions--elastic and inelastic

W=work (J)
F=force (N)
d=displacement (m)
P=power (Watts)
t=time (s)
KE=kinetic energy (J)
PE=potential energy (J)
m=mass (kg)
g=gravity (9.8 or 10 m/s/s)
v=velocity (m/s)
h=height (m)

W = Fd
PE =mgh
P = W/t
KE = 1/2mv²
PE + KE = Total ME

Work, Power, & Energy

​Key Reminders about Energy

• Energy cannot be created or destroyed.

• PE is the energy of displacement

• KE is the energy of motion

• No work done on something that does not move

• Work is only done when the applied for is perpendicular to the direction of movement