Ch. 5 - 8

Question 1

Work done on an object

Answer 1

W = FxΔx
W = (Fcosθ)d

Question 2

Frictional Work

Answer 2

W= -μnΔx

Question 3

Kinetic Energy

Answer 3

1/2mv^2

Question 4

W(net)

Answer 4

ΔKE

Question 5

Gravitational Potential Energy

Answer 5

PE = mgy

Question 6

Work due to non-conservative forces

Answer 6

Wnc = ΔKE + ΔPE
setting Wnc = 0
KEi+PEi=KEf+PEf

Question 7

Spring Potential Energy

Answer 7

PEs = 1/2kx^2

Question 8

Power

Answer 8

P = W/Δt = Fv

Question 9

Linear momentum

Answer 9

p = mv

Question 10

Fnet (in terms of momentum)

Answer 10

F = Δp/Δt

Question 11

Impulse

Answer 11

I = FΔt = mvf - mvi

Question 12

Conservation of Momentum

Answer 12

m1v1i + m2v2i = m1v1f + m2v2f

Question 13

Perfectly Inelastic Collisions

Answer 13

m1v1i +m2v2i = (m1 + m2)vf

Question 14

Elastic Collisions

Answer 14

1/2m1v1i^2 + 1/2m2v2i^2 = 1/2m1v1f^2 +1/2m2v2f^2

v1i - v2i = -(v1f - v2f)

Question 15

Thrust of Rocket

Answer 15

v(exhaust)(∆M/∆t)

Question 16

Velocity of Rocket

Answer 16

vf-vi = v(exhaust)(Mi/Mf)

Question 17

Relation between angle and arc length

Answer 17

θ = s/r
s = displacement along circular arc
r = radius

Question 18

Angular Displacement

Answer 18

∆θ = θf - θi

Question 19

Average Angular Speed

Answer 19

ω = ∆θ/∆t

Question 20

Average Angular Acceleration

Answer 20

α = ∆ ω/∆t

Question 21

Linear Tangential Speed of a Particle Moving in a circular path

Answer 21

vt = r ω
r = radius

Question 22

Tangential Acceleration

Answer 22

at=∆αr

Question 23

Centripetal Acceleration

Answer 23

ac = v^2/r
ac = r ω^2

Question 24

Total Acceleration in Rotation

Answer 24

a = √at^2 + ac^2

Question 25

Centripetal Force

Answer 25

Fc = m(v^2/r)

Question 26

Newton's Law of Universal Gravitation

Answer 26

F = G (m1m2/r^2)

Question 27

Gravitational Potential Energy

Answer 27

PE = -G (Mem/r)

Question 28

Escape Speed

Answer 28

v(esc)=√2GMe/Re

Question 29

Period of a planet in orbit

Answer 29

T^2 = (4π^2/GMs)r^3

Question 30

Torque

Answer 30

τ=rFsinθ τ = rF r = length of the position vector (x)

Question 31

Torque and Two Conditions for Equilibrium

Answer 31

summation of F = 0 | summation of τ = 0

Question 32

center of gravity

Answer 32

x (cg) = summation of (mixi/mi) | y (cg) = summation of (miyi/mi)

Question 33

Torque acting on an object about an angle of rotation

Answer 33

``` τ = mr^2α τ = Iα ```

Question 34

Inertia

Answer 34

I = summation of mr^2

Question 35

Rotational Kinetic Energy

Answer 35

KE = 1/2 I ω^2

Question 36

Angular Momentum

Answer 36

L = I ω

Question 37

Tau in terms of Momentum

Answer 37

summation of τ=∆L/∆t

Question 38

Conservation of Angular Momentum

Answer 38

``` Li = Lf Iiωi = Ifωf ```

Question 39

Rotational Motion under Constant Angular Acceleration

Answer 39

``` ω = ωi + at ∆θ = ωit + 1/2at^2 ω^2 = ωi^2 + 2a∆θ ```