1. General Physics
Midterm Review

2. Study of Energy and matter
Definition of Physics
Study of Energy and matter

3. SI Units
Mass – kilogram
Time – seconds
Length – meter

4. Metric Prefixes Kilo --- one thousand (1000)
Hecto --- one hundred (100)
Centi one hundredth (.01)
Milli --- one thousandth (.001)

5. Significant Digits
10000
342.15
67.00
890.02

6. Significant Digits
Adding and Subtracting --- go by the lowest number of digits to the right of the decimal point
67.03 – =

7. Significant Digits
Multiplication and Division : go by the lowest number of sig. digits
(2.45 x 105)( x 102)=

8. Conversions 120 kg = ______ g 54 km = _______ mm
120 m/s = ______ km/hr
53 cm = ______ m

9. Distance vs. Displacement
Distance: scalar, add total distance traveled
Displacement: vector, difference between starting and ending point

10. Distance vs. Displacement
A person walks 10 m north, 5 m south, then 2 m north. What is the displacement? What is the distance traveled?

11. Graphs (General) Slope = vertical change / horizontal change
Independent variable – manipulated by the experimenter, on the x-axis
Quadratic graph – Parabola, smooth upward curve, y is proportional to x2
Inverse graph – hyperbola
Linear graph – straight line, y and x are directly proportional

12. Position-time graphs Slope = velocity Constant velocity:
Constant acceleration:

13. Position-time graph
At rest:
Slowing Down:

14. Velocity-Time Graphs Slope = acceleration
Area under the curve = displacement
A = l x w
A =1/2bh
Constant velocity:

15. Velocity-time graphs
Constant acceleration:

16. Velocity
V = d/t

17. Acceleration Change in velocity with time a = Dv/Dt Vf = Vi + at
d = vit + 1/2at2

18. At max height, velocity is 0 Vf = -Vi (Perfect Symmetry)
WGUMCD
At max height, velocity is 0
Vf = -Vi (Perfect Symmetry)

19. Distance is proportional to t2
Free Fall
Distance is proportional to t2
all objects accelerate at the same rate regardless of mass, if air resistance is ignored

20. Vectors
Resultant vector – the sum of more than one vector, placed from the tail of the first vector to the tip of the last vector
A student walks 7 m east and then 5 m south, what is the displacement?
Reverse the direction of the initial vector when subtracting

21. Component Method
X component = hcos
Y component = hsin

22. Newton’s First Law Equilibrium – all forces on an object are balanced
Fnet = 0
object is at rest or moving with a constant velocity

23. Newton’s Second Law F = ma
Increase acceleration: decrease mass and increase Force
Weight: gravitational force exerted by a body
W=mg

24. Newton’s Second Law
A snowflake falls with a force of 5 N downward, and experiences a frictional force of 2 N upward. What is the net force on the snowflake?
What must the frictional force on the snowflake be to make it move with a constant speed?

25. Newton’s Second Law
A baseball player slides into second base with a force of 25 N and experiences a frictional force of 4 N. If the player has a mass of 60 kg, what is his acceleration?

26. For every action there is an equal and opposite reaction
Newton’s Third Law
For every action there is an equal and opposite reaction

27. Incline planes
Increasing the angle increases the acceleration and speed of an object
The parallel component of the force of gravity causes an object to slide down the incline plane
Fg = mg
Fg perpendicular = Fgcos
Fg parallel = Fgsin

28. Fnet = Fric + Fg parallel a = Fnet /m
Incline Planes
FN = -Fg perpendicular
Fric = µFN
Fnet = Fric + Fg parallel
a = Fnet /m

29. Projectile Motion (general)
Motion in the horizontal direction is independent of motion in the vertical direction
Velocity in the horizontal direction is constant

30. Type I Projectile Motion
dy= 1/2gt2
dx= vxt
vfy = gt

31. Type II Projectile Motion
Range increases up to 450 (max range) and then decreases after that
Vix = Vi cos
Viy = Vi sin
Vfy = Viy + gt
dy = Viy t + 1/2gt2
dx = vxt
Vf = - Vi