HW_6 - P112 Spring 2007 Homework#6 Due Monday March 5th...

P112 Spring 2007
Homework #6
Due: Monday March 5th, 2007 – At lecture
Note: all of the material on this homework will be
included in Prelim I!
Reading: 5.3, 5.4, 5.5, 14.3
Not all concepts will be covered in class – you are responsible
for all material in the reading and in the homework problems.
Warm-up Exercises:
(Answer only will be marked)
1. A small remote-control car with mass 1.60 kg
moves at a constant speed of v= 12.0 m/s in a vertical
circle inside a hollow metal cylinder that has a radius
of 5.00 m. What is the magnitude of the normal force
exerted on the car by the walls of the cylinder at
a) the bottom of the vertical circle and
b) at the top of the vertical circle?
2. A 0.800-kg ball is tied to the end of a string 1.60 m
long and swung in a vertical circle.
a) During one complete circle, starting anywhere,
calculate the total work done on the ball by
i) the tension in the string,
ii) gravity.
b) Repeat part (a) for motion along a semicircle from
the lowest to the highest point on the path.
Mathematics Exercises:
3 . Let f ( x ) =
1
x
2
"
0.01
( x " 1)
2
. Plot f(x) for 0<x<1. For
what value of x does f(x)=0?
Estimation:
(Marked based solely on logic)
4. The mass of the earth is about 6x10
24
kg. Estimate