Newtons Laws of Motion

Usually three laws are mentioned. There is no law - at least, none that is widely known in the scientific community - called the "fourth law".
There is no such law. There are only three newton laws. :)

If the act together (in the same direction), the resultant force is the sum - 1300 gf (whatever that abbreviation means!). This is the maximum.

If they act in opposite directions, the resultant force is the difference, 300 gf - and this is the minimum.

rest, and that once an object is in motion, it will remain in motion unless acted upon by an external force. This principle is often referred to as inertia.

Uniform motion is what happens in the absence of any net force, so force isn't

needed to maintain uniform motion.

But in our everyday experience on Earth, we always need to supply force in

order to keep something moving, only because there are always forces acting

to stop it, and we have to counteract them.

In the case of your 1,000-kg car, we'd have to know what forces are working

against it ... wind, road friction, air resistance, wheel-bearing friction, etc. ...

and then we'll know how much force we have to supply to cancel those out.

Whatever the answer is, it'll be a continuous thing. The length of time will be

irrelevant.

Isaac Newton stated his second law of motion as: "The force acting on an object is equal to the mass of the object multiplied by its acceleration." This means that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass.

You move in relation to something, for instance, if you take the planet Earth as a reference, then we're not moving, even if you walk around. However, we're moving in relation to the sun because we're on a planet that is.

If you drive a car, you're not moving in relation to the seat you're sitting on, but you are moving in relation to sign posts that you leave behind.

The formula is always the same; the units may change.

In metric (SI) units, you would normally use kilograms for mass, and meters/second2 for acceleration. This naturally results in units of mass x meters/second2 for the force - this happens to be the definition of the Newton.

In any other units, you will similarly have to multiply mass times acceleration to get force; for example, if mass is in pounds, and acceleration in feet/second2, then the force would be in pounds x feet / seconds2. You would have to check whether this unit has a special name - or perhaps you need a conversion factor to convert to some other unit of force. That depends on the specific system of units used.

Yes, it is possible for an object to be traveling with a non-zero velocity even if it is experiencing a net zero external unbalanced force. This is because the object may have inertia, which allows it to maintain its current velocity unless acted upon by an external force.

Zero net force means there is no overall force acting on an object, thus the object will either remain at rest or continue moving at a constant velocity (Newton's First Law). This state of motion is known as equilibrium.

Momentum (P) is the product of mass (m) and velocity (v).

P = m X v

It's easy to get confused by combining metric units (grams) with imperial units (miles per second). Converting all the units to one system first will simplify calculations.

Friction is a force that opposes the motion of an object, so when an object moves forward, friction acts in the opposite direction to slow down the object. The force of friction is proportional to the weight of the object and the surface it is moving across.

Not necessarily. The net force being 0 means the object is in translational equilibrium, but the net torque can still be non-zero if there are unbalanced forces causing rotation.

Final velocity vf is greater than the initial velocity vi . That is vf > vi .

This is an example of acceleration (positive).

Average acceleration aav = [vf - vi]/[tf - ti]

where ti is initial time, and tf is final time.

To increase acceleration for a given net force, you can decrease the mass of the system. This is because acceleration is inversely proportional to mass when net force is constant (F = ma). Alternatively, you can increase the net force acting on the system.

True. Kinematics, which is the study of motion without considering the forces that cause the motion, is a fundamental concept in physics. Many professionals in various fields, such as engineers, architects, animators, and even athletes, use kinematics ideas to analyze and design systems involving motion.

Friction can cause objects to slow down or stop when they are sliding against each other. It can also generate heat as a result of the contact between surfaces. Furthermore, friction can cause wear and tear on the surfaces of objects, leading to their deterioration over time.

Pressing your palms against a wall with full force is an isometric exercise, where you engage your muscles to generate tension without joint movement. This activity can help strengthen your arms, shoulders, and chest muscles.

Every time you see something start to move or change speed, you are seeing Newton's Second Law of motion at work. Also every time you see something change direction of motion, that same law is at work.

In all these cases there is acceleration A of some mass M. And F = MA = net force is the math definition of Newton's Second Law of Motion.

Here is a short list of some example where you see F = MA at work:

• When getting your bicycle up to speed
• When turning a corner in your car (you get thrown to a side)
• When throwing a wad of paper at the girl sitting in front of you in school.
• When dropping a plate of hot lasagna to the floor
• lots and lot more.....

Action and reaction forces act simultaneously. For every action force, there is an equal and opposite reaction force acting on a different object. This principle is known as Newton's third law of motion.

Your question is slightly confusing as you seem to have answered it yourself.

A little extra though, the speed at which the skydiver is now travelling is called terminal velocity and it is the fastest an object can travel with only gravity + air resistance acting on it as forces. Due to differing air resistances everything has its own unique terminal velocity and it is possible to alter it, this is the principle behind a parachute.

You want to use: Acceleration = force/mass.

The force is pushing it north (don't forget to draw your free-body diagram).

Accel. =390/270

Your answer should be 1.4 m/s/s and it is going in the north direction.

That's it =]

First law: The velocity of a body remains constant unless the body is acted upon by an external force

Second law: The acceleration a of a body is parallel and directly proportional to the net force F and inversely proportional to the mass m, i.e., F = ma.

Third law: The mutual forces of action and reaction between two bodies are equal, opposite and collinear.

The net force is 2N north. This is because when you subtract the 5N force south from the 7N force north, you get a resultant force of 2N north.

Static friction occurs between two objects that are not moving relative to each other and prevents the objects from sliding against each other.