With a width of 49 m, the Sydney Harbour Bridge, in Australia, is the
worlds widest long-span bridge. Suppose two charges, 1 2.0 nC and
68.0 nC, are ced 49.0 m apart on the bridge. What is the electric
line between the charges at a distanc
Ms. Todds Honors Physics
Newtons Second Law Problems
1. There are two forces on the 2.0-kg box shown below, but only one is shown. The
figure also shows the acceleration of the box. Find the second force (a) in unit vector
notation and (b) as a magn
TENSION is the name for the force in a stretched spring or string. (Or how
you would feel when you cant figure out a physics problem.)
In one of todays lab activities, you will have the opportunity to measure the
force of tension in t
Solutions to Chapter 6 Review Problems
(a) vo = 95.0 mi/h = 42.46 m/s,
v = 0.
p = p po = mv mvo = 0 (0.250 kg)(42.46 m/s) = 10.6 kgm/s = 10.6 kgm/s opposite vo .
(b) Favg =
mv mv o
= 2.26 10 N .
The negative sign indi
Mrs. Todds Honors Physics
Three ways to solve elastic collision problems
Elastic collision problems can be a pain to solve. Since there are often two unknowns,
v1f and v2f, then you need to have two equations to solve simultaneously.
1. Traditional Method
Answer Key for acceleration problems:
Displacement with constant acceleration
1. 115 meters
4. 41.0 meters
5. 209 km/h
8. 1.30 x 103 meters
9. a) 132 seconds
b) 33.0 seconds
Velocity and displacement with constant acceleration
1. 0.36 meter; 0.22 meter
Constant Acceleration Problems
Spotting a deer up ahead, you brake your car from 75 km/h to 45 km/h over a
displacement of 88 m.
What is the acceleration, assumed to be constant?
What is the elapsed time?
Two trains, one traveling at 72 km/h a
A 10.0 kg crate is pulled up a rough incline with
an initial speed of 1.5 mIs. The pulling force is
100.0 N parallel to the incline, which makes an
angle of 15.0 degrees with the horizontal.
Assuming the coefficient of kinetic friction is
0.40 and the cra
SRTCH YOUR KWOWLE1G
1. Go to the website:
2. Set the softness for Spring 3 so that the spring constant is relatively
small. Using the available masses, find that spring constant. (How
can you take data so that the slope of its graph gives you the spring
1. Pushy Pete applies a 100 N horizontal force to a 20 kg box 50.b m along a rough
floor with coefficient of friction 0.200 between the box and the floor. Calculate:
a) the work done by Pete:
b) the work done on
Use the following vectors to answer items 15.
In the space below, construct a vector diagram showing the total initial
momentum just before the collision.
Consider a collision between two objects. Assume that the initial momentum
of object 1 is represente
jZtt 2?-O L
1. A system of two cables supports a 34.0 kg mass between two walls. The mass is
at rest (static equilibrium!). Refer to the diagram and the angles between the
vertical and each cable.
a) Find T the tension in the lef
4. The inclined plane in the diagram has a coefficient of sliding friction of 0.3 00.
A 50.0 kg box is lifted to the top of the incline, then the box slides down to the
bottom of the incline.
b) The KE at the bottom is
AQ = 1.94 X 1O C
1= l.80X 10
Amtrak has plans to introduce a new electric train in 1999 that will run
between New York and Boston. It wont be superfast, Amtrak says, but it
will be comfortable, very safe, and environmentally f
P=32kW=3,2X10 4 W
In 1994, a group of students at Lawre
nce Technological University, in
Soutlifield, Michigan, built a car that combines conven
tional diesel en
gine and an electric direct-current motor.
The power delivered by the
5. An airplane pilot is going to demonstrate flying in a tight vertical circle. To ensure that
she doesnt black out at the bottom of the circle, the acceleration must not exceed 4.0g.
If the speed of the plane is 50.0 mIs at the bottom of the circle, wh