大学物理双语教学Review of the term
- 格式:pdf
- 大小:356.94 KB
- 文档页数:50
Review of this term
1. Intro, Measurement, Estimating
1.Units, Standards.
2.Order of magnitude, rapid estimation,
Scientific notation.
3.Converting units
1.Reference frames.
2.Displacement, velocity, acceleration.
3.Motion in 1 and 2 dimensions.
4.Vector (i, j, k form).
5.Projectile motion
6.Circular motion
7.Relative motion
[]
j v i v j t y i t x dt
d dt r d v y x r r r r r r +=+== )()(Instantaneous velocity (瞬时速度) :
Instantaneous Acceleration:
22d d d d t r t v a r r r ==
j
a i a a y x r r r
+=⎪⎪⎩
⎪⎪⎨⎧====22
22
d d d d d d d d t y t v a t x t v a y y x x
[]
j v i v j t y i t x dt
d dt r d v y x r r r r r r +=+== )()(Instantaneous velocity (瞬时速度) :
Instantaneous Acceleration:
22d d d d t r t v a r r r ==
j
a i a a y x r r r
+=⎪⎪⎩
⎪⎪⎨⎧====22
22
d d d d d d d d t y t v a t x t v a y y x x
j
v i v v y x ˆˆ+=r o
x
y
0θ0
v r v
r g
r x
v 0r
y
v 0r
(x 0, y 0)
=x a x
x v v 0=g a y −=gt
v v y −=00()
gt v j v i v −+=0000sin ˆcos ˆ
θθr 0
00000sin cos θθv v v v y x ==()()
()2
0020
2
002
00sin 2sin cos gt gt v v gt v v v +−=−+=
θθθr 0
000cos sin tan θθθv gt
v −=
Velocity of projectile motion
The direction of velocity and acceleration.
ω
θr dt
rd dt ds dt r d v =====r r θ
ωˆr v =r Circular motion
dt
v d a r
r =
r
r r r
v r v r
dt
d v dt d v a ˆˆˆˆˆ22ωωθ
θ=====r
O ’
y ’
O
y
x ’
x
P
'
'OO P O OP r r r r r r += Relative Displacement 相对位移
Relative Velocity 相对速度
()'
'''''OO P OO P O OO P O OP P v v dt
r d dt r d dt r r d dt r d v r r r
r r r r r +=+=+=
=Velocity in S
Velocity in S’
Velocity of S’relative to S
S
S’
Relative motion
1.Newton’s laws
2.Mass, inertia.
3.Application of Newton’s laws (in Mechanics and also in Electromagnetism)★
4.Newton’s law of gravitation.
2
2
dt x
d m ma F x x ==∑2
2
dt y
d m ma F y y ==∑2
2dt z
d m ma F z z ==∑N II
k
a j a i a a z y x ˆˆˆ++=r
Chap. 4-6. Dynamics
221r m m G F =Gravitational force
mg F =Gravity
On the earth 2earth earth R mM G mg ≈Which is larger?
1.Work.
2.Work-Kinetic energy theorem.
3.Conservative forces and nonconservative forces.
4.Potential energy.
5.Conservation of energy.