Reading due Wednesday, October 1, 2008 at 8:30 a.m
Read Reese Chapter 5.13 - 5.16 , 6.0 - 6.6 and answer Reading Questions 5 on the Web.
Homework due Tuesday, October 7, 2008 at 4:00 p.m. Homework should be turned in during class or placed in the box outside of the professor's office (Nielsen 343) by 4:00 p.m.
Chapter 5:
Questions: 62
Problems: 39, 60, 64, 65, 67, 71
Chapter 6:
Questions: 5
Problems: 4, 15, 20, 21
Problems A and B: These problems must be solved using the Context-Rich Problem Solutions Outline. Please print copies of the worksheet from the web and use a copy to solve each problem.
Problem A: Over Thanksgiving break you and some friends drive to Colorado to
go skiing. Unfortunately, your car breaks down while driving up a 10° hill.
A driver in a pickup truck comes along and agrees to tow your car to the
nearest town. The truck has a mass of 1800 kg and your car has a mass of
900 kg. You attach a cable from the truck to your car at an angle of 20°
with respect to the road, (so the cable is 30° with respect to the
horizontal). The cable will break if the tension exceeds 4000 N.
The driver of the truck plans to take 10 seconds to tow your car at a
constant acceleration from rest until he reaches a speed of
20 m/s while driving up the 10° slope. Can the driver carry out his plan?
You know that the coefficient of rolling friction between your car tires
and the road is 0.10.
Problem B: A neighbor's child want to go to a neighborhood
carnival. The neighbor is worried about the child's safety because
one of the rides looks dangerous. She knows that you are taking
physics so she asks for your advice. The ride in question has a
10-lb (45 N) chair that hangs freely from a 10 meter long chain
attached to a central pivot point on the top of a tall tower.
When a child enters the ride, the chain is hanging straight down.
When the ride starts up, the chain rotates around the tower at
some angle so it no longer hangs vertically. At the maximum
speed, the chain rotates around the tower once every 3.0 seconds.
When you ask the operator, he says the ride is perfectly safe.
He demonstrates this by sitting in the stationary chair. The chain
creaks, but holds. He weighs 200-lbs (890 N). Has the operator
shown that this ride is safe for a 50-lb (220 N) child?