Physics 1a, Fall 2014
Quiz 4 Solutions
Problem 1
(a) (2 Points)
1
We know that by conservation of energy, Ugrav = Trot + TCM where Trot = 2 I 2 , TCM = 1 M v 2
2
and U = M gy is the potential. But v = r since the spool spins without slipping, so:
M gh =
1
Physics 1A : Quiz 1 Solution Set
Problem 1
(a) First, we should unify the speed and acceleration in the same unit system before doing calculations,
v1 = 20
km
1000 m
50 m
m
= 20
=
5.56
,
hr
3600 s
9 s
s
(1)
2
where v1 is the speed at t1 when the boat ri
Physics 1a, Fall 2014
Quiz 3 Solutions
Song Ming Du
Problem 1
(a) (1 Point)
Energy conservation:
mg(L H) =
1
mv 2 v =
2
2g(L H)
(b) (1 Point)
Hf = H from the ceiling. This is a result from energy conservation.
(c) (2 Point)
Energy conservation:
mgL =
1
mv
Physics 1a, Fall 2014
Quiz 2 Solutions
Problem 1
(a) Let ML and lL be the mass and length of the left rod respectively.
The net torque should be zero. Evaluating the torques about point A:
Since the rods mass is distributed uniformly, the net torque due t
Ph1a Homework Solution 1
Fall 2015
Each homework problem is worth 5 points. Please disregard the point values listed on the problem itself.
Use these instead.
1.1
1.1.a
Frautschi 3.10 (5 points)
(5 point)
We will rst derive the time analytically, then sub
Ph1a Homework Solution 2
Fall 2015
Each homework problem is worth 5 points. Please disregard the point values listed on the problem itself.
Use these instead.
2.1
Frautschi 6.22 (5 points)
2.1.a
(1 points)
2.1.b
(1 points)
The resultant of the two forces