Exam I Practice questions
1) A motorist makes a trip of 180 miles. For the first 90 miles she drives at a constant speed of 30 mph. At what constant
speed must she drive the remaining distance if her average speed for the total trip is to be 40 mph?
2) A
Practice problems #3
1) A wooden
raft has a mass of 50 kg. When empty it floats in water (density
with
69% of its volume submerged. What mass of sand can be put on the raft without it sinking?
is suspended from a scale reads 20.0 N. A beaker of water (hav
Homework 3
(47) What average force is required to stop a 950kg car in 8.0 s if the car
is traveling at 95 km/h?
Solution:
First find the average acceleration
aavg =
v
v0
t
=
0
95 km/hr
=
8s
3.3 m/s2
The average force on the car is found from Newtons sec
Homework 4
(57) A car drives straight down toward the bottom of a valley and up the
other side on a road whose bottom has a radius of curvature of 115 m. At
the very bottom, the normal force on the driver is twice his weight. At what
speed was the car tr
Homework 1
(28) A horse trots away from its trainer in a straight line, moving 38 m away
in 9.0 s. It then turns abruptly and gallops halfway back in 1.8 s. Calculate
(a) its average speed and (b) its average velocity for the entire trip, using
away from
1) A very light ideal spring with a spring constant (force constant) of 2.5 N/cm pulls horizontally on an 18kg box that is
resting on a horizontal floor. The coefficient of static friction between the box and the floor is 0.65, and the coefficient of
kin
Physics 110 Midterm II
April 13, 2016
SOLUTIONS
Show ALL your work clearly and neatly! Do each problem on a separate sheet and
use the back if you need more space.
1. A block of mass 10 kg is pulled up 10 m by a force of 100 N up an incline as shown in
th
Homework 5
(69) A box of mass 4.0 kg is accelerated from rest by a force across a floor
at a rate of 2.0 m/s 2 for 7.0 s. Find the net work done on the box.
Solution
Assume that the box starts from rest.
d=x
1
1
x0 = v0 t + at2 = 0 + 2.0 7.02 = 49 m.
2
2
Homework 7
(8  5) The platter of the hard drive of a computer rotates at 7200 rpm (rpm
= revolutions per minute = rev/min).
Solution
(a) What is the angular velocity (rad/s) of the platter?
7200 rev
2 rad
1 min
!=
= 754 rad/s.
min
rev
60 s
(b) If the rea
Homework 7
(7  10) An object at rest is suddenly broken apart into two fragments by
an explosion. One fragment acquires twice the kinetic energy of the other.
What is the ratio of their masses?
Solution
Momentum will be conserved in one dimension in the
Homework 2
(35) V is a vector 24.8 units in magnitude and points at an angle of 23.4
above the negative xaxis. (a) Sketch this vector. (b) Calculate Vx and Vy .
(c) Use Vx and Vy to obtain (again) the magnitude and direction of V . [Note:
Part (c) is a
OKPARE 1
NEWTONS
LAW OF
MOTIONS
Its Applications in the World Around Us
Daniel Okpare
PHYSICS 11
OKPARE 2
Daniel Okpare
Dr. Jalil Moghaddasi
PHY 11
Newtons Law of Motions: Its Applications in the World Around Us
Sir Isaac Newton was revolutionary during t
General Physics: Introductory Course in Mechanics, Heat, and Sound (Uses College Algebra)
PHYSICS 110

Spring 2016
PHY215 Sec 123 Extra Credit (Spring 2016)
Science Department, Professor Chiaki Yanagisawa
Name_
Solve up to 5 problems. Submit your answers and solutions on Tuesday, May 3 in the class. No
delayed submission will be accepted.
1. Sound waves are produced b
General Physics: Introductory Course in Mechanics, Heat, and Sound (Uses College Algebra)
PHYSICS 110

Spring 2016
Problem #1:
PART A: Calculate the centerofmass of the array of point masses indicated below. Use the XY coordinate system indicated on
the diagram. The smaller two masses are m=2 kg each and the two largest masses are M=3 kg. The four masses are connect
General Physics: Introductory Course in Mechanics, Heat, and Sound (Uses College Algebra)
PHYSICS 110

Spring 2016
Solutions for Exam 2
Problem #1:
Using the XY coordinate system drawn on the image of the four mass system, we can calculate two moments of inertia; one
about a vertical axis which the system can rotate (rotation around the yaxis) and one about a horizo
General Physics: Introductory Course in Mechanics, Heat, and Sound (Uses College Algebra)
PHYSICS 110

Spring 2016
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