questions: force and motion I problem 1 The figure below is an overhead view of a 12 kg tire that is to be pulled by three ropes. One force (Fl, with magnitude 50 N) is indicated. Orient the other two forces F2 and F3 so that the magnitude of the resulting acceleration of the tire is least, and find that magnitude if (a) F2 = 30N, F3= 20 N; (b) F2= 30 N, F3 = 10 N; and (c) F2 = F3 = 30 N.

problem 2 A weight-conscious penguin with a mass of 15.0 kg rests on a bathroom scale (see figure below). What are (a) the penguin's weight W and (b) the normal force N on the penguin? (c) What is the reading on the scale, assuming it is calibrated in weight units?

problem 3 If a nucleus captures a stray neutron, it must bring the neutron to a stop within the diameter of the nucleus by means of the strong force. That force, which "glues" the nucleus together, is essentially zero outside the nucleus. Suppose that a stray neutron with an initial speed of 1.4 X 107 m/s is just barely captured by a nucleus with diameter d = 1.0 X 10-14 m. Assuming that the force on the neutron is constant, find the magnitude of that force. The neutron's mass is 1.67 X 10-27 kg.

problem 4 Sunjamming. A "sun yacht" is a spacecraft with a large sail that is pushed by sunlight. Although such a push is tiny in everyday circumstances, it can be large enough to send the spacecraft outward from the Sun on a cost-free but slow trip. Suppose that the spacecraft has a mass of 900 kg and receives a push of 20 N.(a) What is the magnitude of the resulting acceleration? If the craft starts from rest, (b) how far will it travel in 1 day and (c) how fast will it then be moving?

problem 5 A 40 kg girl and an 8.4 kg sled are on the surface of a frozen lake, 15 m apart. By means of a rope, the girl exerts a horizontal 5.2 N force on the sled, pulling it toward her. (a) What is the acceleration of the sled? (b) What is the acceleration of the girl? (c) How far from the girl's initial position do they meet,...

...Chapter 4 Newton’s Laws
Conceptual Problems
1 • While on a very smooth level transcontinental plane flight, your coffee cup sits motionless on your tray. Are there forces acting on the cup? If so, how do they differ from the forces that would be acting on the cup if it sat on your kitchen table at home? Determine the Concept Yes, there are forces acting on it. They are the normal force of the table and the gravitational pull of Earth (weight). Because the cup is not accelerating relative to the ground, the forces are the same as those that would act on it if it was sitting on your table at home. 2 • You are passing another car on a r highway and determine that, relative to you, the car you pass has an acceleration a to the west. However, the driver of the other car is maintaining a constant speed and direction relative to the road. Is the reference frame of your car an inertial one? If not, in which direction (east or west) is your car accelerating relative to the other car? Determine the Concept No. You are in a non-inertial frame that is accelerating to the east, opposite the other car’s apparent acceleration. 3 • [SSM] You are riding in a limousine that has opaque windows that do not allow you to see outside. The car is on a flat horizontal plane, so the car can accelerate by speeding up, slowing down, or turning. Equipped with just a small heavy object on the end of a...

...The Effects of Force and Mass on an Object’s Acceleration
Abstract: In this lab there were two principals investigated. The first was the relationship between applied force and acceleration. The second was the relationship between mass and acceleration. To study these two relationships, my partners and I used a dynamic cart with added mass on it. This cart was then attached to a pulley system on a “frictionless track” where it was pulled by a string bearing mass over the edge of a table. In the first relationship tested, applied force and acceleration, mass was moved from being on the cart to being on the end of the pulley. My partners and I measured the acceleration with the LabQuest computer every time the cart was released. In order to test the relationship between mass and acceleration, my group added different amounts of mass to the cart and measured the changes in acceleration. From all of the data collected we concluded that force and acceleration have a direct, linear relationship. We also determined that mass and acceleration have an inverse, quadratic relationship.
Background:
When my lab partners and I started this lab, we came in knowing some background information on what we were doing and the concepts involved. We knew that we had to determine...

...Acceleration from Gravity on an Incline
I. Introduction:
Acceleration is the rate of change of the velocity of a moving body. Galileo was the first person to actually experiment and examine the concept of acceleration back in the seventeenth century. Acceleration can be determined by calculating the gravity and an incline. An incline is slope that is deviated between horizontal and vertical positions. Gravity is the naturalforce of attraction towards the center of the earth. Because of this, we are able to calculate acceleration.
II. Purpose:
The purpose of this experiment was to determine the relationship between the angle of an incline and the acceleration of a cart rolling down a ramp. Once our results were recorded, we were able to examine them to determine if our results were based upon gravity’s natural pull.
III. Procedure/Materials
First, we began by setting up our ramp and cart. We then used a motion detector and repeated our experiment five different times each with a different incline to roll the cart down. We recorded data after each time.
Lab Quest
Track
Dynamics Kit
Ring Stand
Vernier Motion Detector
Meter Stick
Calculator
IV. Data
Height, h (cm)
Length, x (cm)
Sin Ѳ
Acceleration Trial 1
(m/s2)
Acceleration Trial 2
(m/s2)
Acceleration Trial 3
(m/s2)
Average...

...Investigation (mass and force)
Aim: To show the relationship between Mass, the force acting on it, and acceleration by gathering data through investigations.
Hypothesis: As Mass increases, Acceleration Decreases. Therefore, Acceleration is inversely proportional to mass.
Introduction
A force is a push or pull acting upon an object, as a result of its interaction with another object. In a state of motion, an object experiences different forces which influences its movement. There are many different types of forces which act upon an object; a normal force, a gravitational force, the applied force of the object, and the force of friction.
A normal force is the force which balances the weight of an object on a surface, it travels in the opposite direction as Gravitational forces but always has the same magnitude.
Gravitational forces are magnetic forces from the Earth which pull an object down to the Earth .The normal acts as a balance which keeps the object on a surface.
The applied force is the force which an object applies onto another object. On motor vehicles, the engine turns the wheels, exerting force onto the road in order to move.
The frictional force is the force...

...What is Force?
In physics, a force is any influence that causes an object to undergo a certain change, either concerning its movement, direction, or geometrical construction. It is measured with the SI unit of newtons and represented by the symbol F. In other words, a force is that which can cause an object with mass to change its velocity(which includes to begin moving from a state of rest), i.e., to accelerate, or which can cause a flexible object to deform. Force can also be described by intuitive concepts such as a push or pull. A force has both magnitude and direction, making it a vector quantity.
The original form of Newton's second law states that the net force acting upon an object is equal to the rate at which its momentum changes with time.[1] If the mass of the object is constant, this law implies that the acceleration of an object is directly proportional to the net force acting on the object, is in the direction of the net force, and is inversely proportional the mass of the object. As a formula, this is expressed as:
where the arrows imply a vector quantity possessing both magnitude and direction.
Related concepts to force include: thrust, which increases the velocity of an object; drag, which decreases the velocity of an object; and torque which produces changes in rotational speed of an object....

...2ND LAW (1‑D MOTION PROBLEMS):
1) A 90 kg woman stands in an elevator. Find the force which the floor of the elevator exerts on the woman a) when the elevator has an upward acceleration of 2 m/sec2; b) when the elevator is rising at constant speed; c) when the elevator has a downward acceleration of 2 m/sec2.
Solution: We have a simple application of Newton's 2nd Law of motion. We need only draw the vector force diagram for all forces acting on the woman. There are only two forces present, these are:
Fearth on woman = W = mg .
Ffloor on woman = N .
We select a CS with 'y' chosen upwards. The basic equation involved with the problem is the 2nd law:
Fnet = m a .
a). ay 0; Fy = N ‑ mg = m ay N = m(g + a) = (90)(9.8 + 2) = 1062 N.
b). a 0; Fy = N ‑ mg = m ay N = m(g + a) = (90)(9.8 ‑ 2) = 702 N.
c) a = 0 (equilibrium) Fy = N ‑ mg = 0 N = mg = (90)(9.8) = 882 N.
2) A Boeing 707 jet aircraft has a takeoff mass of 1.2 x 105 kg. Each of its four engines has a net thrust of 75 kN. Calculate the acceleration and the length of the runway needed to become airborne if the takeoff speed is 73 m/s. (Neglect any frictional forces and air‑resistance)
Solution: Neglecting air‑resistance & frictional forces then the...

...Chapter 2
Forces
To study the effect of forces acting on particles.
2.1 Equilibrium of a Particle
2.2 Free Body Diagram
2.3 Force Vectors
2.4 Forces in a Plane
2.5 Forces in Space
Expected Outcomes
• Understand the condition for a particle to be in static
equilibrium
• Able to construct free body diagrams
• Able to solve for the forces acting on a static particle
2.1
Equilibrium
of a Particle
www.classical.com/features
2.1.1 Condition for the
Equilibrium of a Particle
• Particle is at equilibrium if it is
a) At rest
b) Moving at constant a constant velocity
2.1.1 Condition for the Equilibrium
of a Particle
(a) Equilibrium at rest
• Newton’s first law of motion
∑F = 0
where ∑F is the vector sum of all the forces acting on the
particle
Even Univ.
Graduates
(a) Equilibrium at rest
• Newton’s Law of
Motion
• 1st law – a particle
originally at rest, or
moving in a straight
line with constant
velocity, tends to
remain in its state
provided the particle
is not subjected to an
unbalanced force.
http://www.jameslogancourier.org/index.php?blogid=1&archive=2006-3-21
2.1.1 Condition for the
Equilibrium of a Particle
(b) Equilibrium at motion
• Newton’s second law of motion
∑F = ma
• When the force fulfill Newton's first law of motion,
ma = 0
a=0
therefore, the particle is moving in...

...com.au mail@keepitsimplescience.com.au
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