Force is an agent which produces or tends to produce motion in an object, stops or tends to stop , motion of an object

Newton's 1st law of motion:
If an object is at rest, will remain at rest until or unless an external force act on it. If an object is in motion , it continues its motion until or unless an external force act on it Newton's 1st law of motion is also called first law of inertia.

Inertia:
The tendency of an object to resist any change in its state of motion or rest is called inertia. Inertia is the measure of mass in an object.
Heavier object are difficult to bring in motion or in rest because they've greater inertia.

Newton's 2nd law of motion:
Force produces acceleration in an object in its own direction. The acceleration is directly proportional to the force and inversely proportional of the mass of the object.

Resultant force is unbalanced force.
F=ma , where F is the resultant force.

Q: the mass of a boy n his bicycle is 30kg, wants to accelerate at 1.5per sec square if the opposing force is acting on both is 40N Find the force needed for this acceleration.

Q2: a car of weight 50,000N is moving with a uniform speed of 20meters per sec The opposing force is acting on the car is 600N
Find:
a: the force applied by the engine
b: if the engine stops working, find deceleration

Q3: a car of weight 50,000N is moving on a straight road, the force applied by the engine is 2000N and the opposing forces acting on it is 800N Find acceleration

Newton's 3rd law of motion:
For every action, there is always an equal or opposite reaction " the force exerted by object A on B is always equal n opposite to the force exerted by B on A"

Friction:
When any objects slides or roles on the surface of another object which experiences a force opposite to its direction of motion. This opposing force is called Force of Friction.

Causes of friction:
If the objects are observed on the electronic microscope, the...

...PhysicsNotes
* If the vector of all sums is precisely zero the object could be still moving
* IF an elevator fell , the passengers would be trapped to the ceiling of the elevator seeing as there is no air resistance , false
* Constant speed = no acceleration = sum of all net forces is zero
* An object in orbit around the earth is not truly weightless
* Sitting half as far away from your class mate the gravitationforce is four times as strong. (re2)
* Newton’s First Law- inertia an object that is not moving will remain at rest (ex: and apple hanging from a tree)
* The reason you head feels like it jerks back ward is when pulling away from a stop sign is due to Newtons first law
* If two forces that are identical in strength but exactly opposite in direction act on the same object that object will not necessarily be motionless
* When drawing a FBD, the net force must not be included
* 2 people pushing an object across a frictionless surface will result in twice the acceleration than if only one was pushing. Assume the object slides in both cases and both people push with same force (true)
*
Types of forces:
* Dynamics: the study of motion
* No movement forces are balanced
* Applied Force: a force that results when one object makes contact with another...

...Return to Info on Free-body diagrams
Return to on-line Force Description List
2. A girl is suspended motionless from the ceiling by two ropes. A free-body diagram for this situation looks like this:
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Return to on-line Force Description List
3. An egg is free-falling from a nest in a tree. Neglect air resistance. A free-body diagram for this situation looks like this:
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Return to Info on Free-body diagrams
Return to on-line Force Description List
4. A flying squirrel is gliding (no wing flaps) from a tree to the ground at constant velocity. Consider air resistance. A free-body diagram for this situation looks like this:
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Return to Info on Free-body diagrams
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5. A rightward force is applied to a book in order to move it across a desk with a rightward acceleration. Consider frictional forces. Neglect air resistance. A free-body diagram for this situation looks like this:
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Return to on-line Force Description List
6. A rightward force is applied to a book in order to move it across a desk at constant velocity. Consider frictional forces. Neglect air resistance. A free-body diagram for this situation looks like this:
...

...http://www.physicsclassroom.com/mmedia/circmot/rcd.cfm
What is ‘g force’ in physics?
G, in physics, a symbol relating to gravity. A capital G indicates the gravitational constant, as explained in the article GRAVITATION. A lower-case g stands for the acceleration imparted by gravity at the earth's surface. An acceleration of 1 g is 32. 1 feet per second per second (9.8 m/s2).
Fliers and astronauts may experience accelerations many times larger than 1 g. These accelerations are usually expressed in multiples of g, such as 2g, 3g, etc. For example, when the speed of a space vehicle increases 96.3 feet per second (29.4 m/s) during a second of travel, the vehicle is said to be accelerating at 3 g's. An astronaut in the space vehicle would experience a force, called a g force, three times as strong as the force of gravity at the earth's surface.
Great effort is required to move parts of the body against the g force produced at an acceleration of 3 g's. Tolerance to even greater accelerations depends on the position of the individual in relation to the g force. A person in an upright position with respect to the g force suffers temporary vision loss at about 4 g's, and loss of consciousness at 5 to 8 g's, because the amount of blood reaching the brain is reduced. A person in a lying position with respect to the g force can endure up...

...I noticed that I have not described the rule of F=ma in either the last email or this one. Where would you suggest it be described?
Somehow the details of adding forces and balanced forces were missed in the last email and also it did not make perfect sense for me to note. As far as I am concerned the khan academy does not lecture it so I am not too sure in what to do about this.
I am assuming finding velocity is the sole purpose of applying the law of conservation of momentum. Is this true?
I also would like to note that a graph could not be drawn in some situations again due to me lacking the technology to send photos of handwritten notes. Hence there is sadly no examples of a problem for translational equilibrium and for the force-time graph in which impulse can be identified.
I also have referred to explosions as divisions. Is this appropriate?
Newton's First Law of Motion:
A body will remain at rest or moving with constant velocity unless acted on by an unbalanced force.
Example:
• Q: while traveling in train if one throws a ball up it lands on his palm though the train is moving. my doubt is that though the ball is detached from motion how does it manage to land on his palm though he is moving along with the train?
• A: he ball lands on your hand because the ball is, in reality, traveling at the same velocity as the train,...

...
Free Fall
Rachel Shea
Physics 131 Lab, QL
Hasbrouck 210
Sept. 21, 2014
Abstract
This experiment measures the study of motion by observing the force of gravity acting solely upon an object, and also measures reaction time. If an object is in free fall, the only force acting upon it is gravity. The object used in this experiment was a golf ball that provided some acceleration when dropped. A sensor positioned underneath a table recorded the golf ball’s pattern of motion, when dropped. The main objective of performing this experiment is to measure the velocity and position of the ball to eventually find the acceleration of free fall. A computer program called, DataStudio, was used to create a graph of position vs. time and a graph of velocity vs. time. The second part of the experiment involved randomly dropping a ruler and having your partner catch it to determine reaction time.
Questions
1. The parabolic curves open upward instead of downward because of the golf balls movement over time: where it is dropped from, to where it ends up. The ball begins close to the sensor, then drops to the ground, then bounces back up closer to sensor again, therefore the bounces correspond with the bottom curves of the parabola. If the data were collected from the floor then the curve would open downward. But because the sensor graphs the position from the sensor, the curve was upwards.
2.
-4572009207500
The slope of the velocity...

...Change of momentum is related to the forces acting on the vehicle or the driver. Explain how we can increase the safety of the driver based on the above statement.
Momentum of an object can be defined as the product of the mass of the object and its velocity. The unit of momentum is kgms-1. Momentum is a vector quantity, and it has both magnitude and direction. Its direction is the same as the direction of the object’s velocity.
Momentum = mass x velocity
p = m v
Momentum can also be defined as inertia in motion. To have momentum, the object must be moving. Momentum tells how hard it is to get something to stop or to change directions. Every moving object has momentum and any object with momentum is going to be hard to stop. To stop such an object, it is necessary to apply a force against its motion for a given period of time. The more momentum the object has, the harder it is to be stopped. Thus, it would require a greater amount of force or a longer amount of time or both to bring such an object to a halt. Force acting for a given amount of time will change an object's momentum. As the force acts upon the object for a given amount of time, the object's velocity is changed, and hence, the object's momentum is changed.1 If the force acts opposite the object's motion, it slows the object down. If the force acts in the same direction as the object's motion, then the...

...Physics Lab Report
Experiment M3 Centripetal Force
School: La Salle College
Class: 6G
Group members (Group 7): Carson Ho, Tang Yui Hong, John Yu, Justin Kwong
Date: 1 / 10 / 2014
Report is written by: Tang Yui Hong 6G (27)
Title
Centripetal Force
Objective
To verify the equation for centripetal force
Apparatus
Instrument
Descriptions
1 rubber bung
circular, cylinder
screw nuts and wire hook
/
1 small paper marker
/
1 rule
1 metre
safety goggles
/
adhesive tape
/
1 glass tube
~ 15 cm
1 nylon string
1.5 m, inextensible
1 stop-watch
/
1 triple beam balance
/
scissors
/
Sketching of the set-up
Theory
Centripetal force F is the net force causing the centripetal acceleration of an object performing uniform circular motion. Its magnitude is given by the equation: F = mrω2
When an object is whirled in horizontal circular motion in mid-air with a piece of string (as shown in figure 1 above), the centripetal force on the object is provided by the horizontal component of tension in the string:
2
=>2 (since r = L)
Procedure
1 A triple beam balance is used to find the mass of the rubber bung, the screw nuts and the wire hook respectively. The total weight of the screw nuts and the wire hook provided the tension T in the nylon thread.
2 The centripetal force apparatus is set up (Figure 2). The paper marker is used to...

...Leaving Cert Physics Acceleration, Force, Momentum, Energy long questions
Remember to photocopy 4 pages onto 1 sheet by going A3→A4 and using back to back on the photocopier
2012 - 2002
Solutions to ordinary level questions begin on page 11
Solutions to higher level questions begin on page 19
Velocity
2010 Question 12 (a) [Higher Level]
(i) A student holds a motion sensor attached to a data-logger and its calculator.
List the instructions you should give the student so that the calculator will display the graph shown in Fig 1.
(ii) The graph in Figure 2 represents the motion of a cyclist on a journey.
Using the graph, calculate the distance travelled by the cyclist and the average speed for the journey.
Equations of motion (vuast)
2004 Question 6 [Ordinary Level]
(i) Define velocity.
(ii) Define acceleration.
(iii) Describe an experiment to measure the velocity of a moving object.
(iv) A cheetah can go from rest up to a velocity of 28 m s−1 in just 4 seconds and stay running at this velocity for a further 10 seconds.
Sketch a velocity−time graph to show the variation of velocity with time for the cheetah during these 14 seconds.
(v) Calculate the acceleration of the cheetah during the first 4 seconds.
(vi) Calculate the resultant force acting on the cheetah while it is accelerating.
The mass of the cheetah is 150 kg.
(vii) Name two forces acting on...