091613
Laws of motion (I)
1) What is a Force? (or, why things move)
2) More on Reference Frames and Newtons 1st Law
3) Mass
4) Newtons 2nd Law
Why do Things Move?
Up until now we have been discussing
Page 1
D. We calculate work to find mechanical energy:
= = ( + ) (. ) + . ) ( )(. ) = . =
C. He performs the same amount of work. However, with a small rear sprocket the force is higher but the
dist
1) B: 11.4 h
t = d/v = (630 mi)/(55.3 mi/hr) = 11.4 hr
2) A: increase
g increases as you get closer to the surface of the Earth, as is approximately 9.8 m/s2 at the Earths surface.
3) C: instantaneous
3)
a)
At r > r2, the entire charge Q is enclosed. Thus the potential is:
=
=
b)
By Gausss law, we get that:
=
=
=
( ( )
( )
= () =
( )
( + )
=
Where is the charge density
c)
At r < r1, qenc
a)
We apply Keplers third law:
=
(. + . ) (. )(. )
=
= .
b)
We apply the formula for gravitation:
=
(. )(. )
=
= . /
(. + . )
c)
Weight is equal to mass times acceleration due to gravity:
= =
1. Suppose we built a base on one of jupiter's small moons (a distance of 5AU from the Sun). How
fast would you have to launch a rocker from there to reach a moon of Saturn (10 AU away)?
(assume the s
a)
We use an equation that relations angular velocity to angular acceleration:
= +
= (
) + (. )
= . /
b)
We use an equation that relations angular displacement to angular acceleration and velo
Here we want to find the area under the curve from t = 0 to t = 4 sec, since the integration of
angular velocity with respect to time gives angular displacement:
= (
) ( ) + (
) ( ) = = .
a)
We use
090913
Physics 151
Vectors
1) Coordinate Systems
X,y graph
-(x1,y1)
-any coordinate system is composed of orthogonal (perpendicular) directions
-Cartesian coordinates
-Polar Coordinates
- We use r and
1. the speed of galaxies can be measured by using
a. hubbles constant
b. speed of light
c.doppler shift
d. parallax
2. the reddish skies during a "sunset" can be explained by the wave effect:
a. red s