Physics – 1st Semester Review

Unit 1: Kinematics – Chapter 2-3

How things move

Displacement – distance from origin (direction significant)

Velocity – rate position changes

Acceleration – rate velocity changes

o To determine if object is speeding up or slowing down use “thumb rule”

Equations:

x = xo + vot +

at

2

v = vo + at

v2 = vo

2 + 2ax

Standard Units: meters, kilograms, seconds

Motion Graphs

position time graph slope velocity

velocity time graph slope acceleration

acceleration time graph area under curve velocity

velocity time graph area under curve position

Sample problems

Page 52-54: 34, 39, 40, 47, 51, 53, 55, 59, 60

Page 80-84: 54, 57, 58, 61, 63, 66, 68, 74, 79, 80, 81, 88, 89, 93, 96, 102

Physics – 1st Semester Review

Unit 2: Mechanics – Chapter 4-5

Why things move

Equations

Newton’s First Law: F = 0 {equilibrium}

Newton’s Second Law: F = ma

Newton’s Third Law: Fab = -Fba

Friction: f = N

Standard Units: kilogram, Newton

Force Diagrams

Draw all forces acting on an object from the center of the object in the direction the force acts

and proportional to its strength.

Find components of forces acting in the i and j directions. (vector components)

Apply Newton’s laws.

Types of Forces

Friction: depends on the surfaces in contact and the normal force

o Static friction acts when the object is not moving, can vary from 0 up to sN

o Kinetic friction acts when the object is moving, is always equal to kN

Tension: force transmitted in a string or rope, changes direction over a pulley

Sample problems

Page 112-116: 41, 43, 46, 47, 53, 61, 64, 68, 69, 70, 86, 87, 89

Page 140-144: 48, 85, 90, 92, 99, 101

Physics – 1st Semester Review

Unit 3: Two Dimensional Motions – Chapter 6

Projectile Motion

Object moves only under the influence of gravity

Horizontal and vertical motion are independent

Symmetric motion

vy = 0 at max height

Equations

i j

x = xo + voxt y = yo + voyt -

gt

2

vx = vox vy = voy - gt

vy 2

= voy2 - 2gy

Circular Motion

Velocity is constantly changing direction, therefore it is constantly accelerating

Acceleration is toward the center of the circle

A force is necessary to maintain circular motion (force is toward center)

Period (T) is time for one revolution

Equations

Fc = mac

Relative Motion

Different observers may see different motions

At high speeds (v close to c) the connection between space and time is evident

o All observers agree on the speed of light

o Moving clocks run slow

o Lengths contract along the direction of motion

Sample problems

Page 164-168: 33, 35, 48, 56, 61, 70, 80, 81

Physics – 1st Semester Review

Unit4: Gravitation and Rotational Motion – Chapter 7-8

Gravitation

Building on the ideas of Copernicus and the data of Tycho Brahe, Johannas Kepler discovered

Three Laws of Planetary Motion

o Law of Orbits

o Law of Areas

o Law of Periods

Isaac Newton discovered gravity is the attractive force between all objects with mass

Henry Cavendish determined the value of G, thus allowing the mass of Earth to be calculated

Equations

Fg =

(

) = (

)

Rotational Motion

Concerned with spinning objects and has direct analogs to linear motion

Linear Rotational

Quantity Symbol:Units Symbol:Units

Displacement x:meters :radians

Velocity v:meters/second :radians/second

Acceleration a:meters/second2 :radians/second

2

Force F:Newtons :Newton-Meter

Equations

= o + ot +

t

2

= o + t

2

= o2 + 2

= rFsin; using the right hand rule for direction

Sample problems

Page 190-194: 24, 26, 27, 32, 36, 40, 41, 69, 70

Page 222-226: 48, 50, 54, 61, 73, 77, 81

Physics – 1st Semester Review

Unit 1 Sample problems

Page 52-54: 35, 39, 40, 47, 51, 53, 55, 59, 60

Page 80-84: 54, 57, 58, 61, 63, 66, 68, 74, 79, 80, 81, 88, 89, 93, 96, 102

Unit 2 Sample problems

Page 112-116: 41, 43, 46, 47, 53, 61, 64, 68, 69, 70, 86, 87, 89

Page 140-144: 48, 85, 90, 92, 99, 101

Unit 3 Sample problems

Page 164-168: 33, 35, 48, 56, 61, 70, 80, 81

Unit 4 Sample problems

Page 190-194: 24, 26, 27, 32, 36, 40, 41, 69, 70

Page 222-226: 48, 50, 54, 61, 73, 77, 81

Physics – 1st Semester Review

ANSWERS TO SAMPLE PROBLEMS

Page 53-54

35, 39, 40 not

included

Page 80-84

54, 57, 58,

61, 63, 66

NI

Page 112-116

41, 43, 46, 47, 53 NI

Page 140-

144

48 NI

Page 164-

168

33, 35 NI

Page 190-

194

24, 26, 27,

40, 41 NI

Page 222-

226

All included

47: Moolinda,

Dolly, Bessie,

Elsie

51: 11m

53: 1.8min

55: Straight

line starting at

left and going

up as it goes

right, time

interval goes to

1.9 s.

59: a. 6h,

b.

2.6x102km

c. 7.3h

60:

a. answers

vary

b. from 8 to

24s, 53 to

56s and at

43s

68: a=0

74:First

should be

straight,

Second a

backwards z

with a line

through it,

Third a

forwards z

79:

a.

5x101km/h

b. 48km/h

80: 8m/s2

81: 33m/s

88: 180m/s

89: a. 43m

b. 43m

93:

1.6x103m

96: Positive

102: a.

6.2m

b. 11m/s

61: 6.9x103N

64: 2.5x102kg

68: a. 45m/s2 b.

3.9x104N c. 3.1x10

3N

69: a. 5.2x102N

b. 4.1x102N

c. 4.1x102N

d. 5.2x102N

e. Depends

Fscale=(53kg)(9.8m/s2+a)

70: 250N doesn’t hold

86: a. -6x103m/s

2

b. -8.7x102N

c. same but opposite

direction

87: a. 48m/s2

b. 4.3x102m/s

89: a. 9.8m/s2

b. 9.8 m/s (up)

c. -49N (down) just

instrument weight

d. 1.0x101s after release

85: 640.3N

at 11.3o

degrees

90: 0.255

92:

a. 1x101N

b. 0.20

99: 123N

101:

a. 1.3m/s2

b. 140N

48: doubled

FT=mae’

56: a. 31m

b. 2.1x102m

61:

a. 9.65m/s2

b.5.9x103N

70: a. 5m/s,

53o to shore

b. parallel:

3m/s

Perpendicular:

4m/s

80: a. 14.6 N

b. 1.4m/s

81: 53m or

4x101m

32:

gravitational

attraction to

the central

body.

36: the value

of g would

double.

69: 18AU

70:

a. 2.24x1015

m2/s

b. 2x1011

m2/s

48: It is

constant.

50: Yes

54:

0=E<D<C

<B<A

61:

identical

linear

velocities

but angular

velocities

are different

b/c [w=v/r]

73:

51rad/s

77:

17.5cm/s

81: 23N

Some answers were not included because they are conceptual and you should be able to figure them out by now.