BBC Bitesize - GCSE Combined Science - Forces, acceleration and Newton's laws - AQA - Revision 3
Original question "Does anyone know how to calculate the velocity of an object of a given, constant mass after using AddForce? There is no. Since acceleration is the change in velocity divided by time, you can connect the two concepts with the following relationship: force = mass x (velocity / time). Explains Newton's Second Law of Motion in terms of the equation F=ma. The net force on an object is equal to the mass of the object multiplied by the . The final velocity is equal to the initial velocity plus the acceleration multiplied by time.
Scalars and Vectors Mass is a simple kind of quantity. You can have large masses, tiny masses and in-between masses. Scientists call simple quantities scalars because one number will describe it.
How to Calculate Velocity From Force & Distance | Sciencing
Force and acceleration, however, are more complicated. They have both a size and a direction. A TV weather forecaster, for example, talks about a wind coming from the west at 20 miles per hour.
This is the velocity speed vector of the wind. To fully describe a force or acceleration, you need both the amount and the direction.
Push on an object of a certain mass, and it accelerates based on the amount of force and mass. A small force with a large mass results in a slow acceleration, and a large force with a small mass gives a fast acceleration.
A force of zero on any mass gives zero acceleration.
- Meaning of Force
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Keep in mind that several forces can be involved at the same time. For example, you tie a rope around a boulder and pull with all your might.
The force of friction between the boulder and the ground cancels out the force of your pull.
You need a much bigger force, such as from a tractor, to move the boulder. For rocket and jet engines, the term "thrust" is often used. Weight This is the force exerted by gravity on an object.
It depends on the mass of the object and varies slightly depending on where it is located on the planet and the distance from the center of the Earth. An object's weight is less on the Moon and this is why the Apollo astronauts seemed to bounce around a lot and could jump higher. However it could be greater on other planets. Weight is due to the gravitational force of attraction between two bodies. It is proportional to the mass of the bodies and inversely proportional to the square of the distance apart.
In engineering, this force acting on a structure is known as a load. Tensile or Compressive Reaction When you stretch a spring or pull on a rope, the material exerts an equal reactive force pulling back in the opposite direction. This is known as tension. If you try to compress an object such as a spring, sponge, gas or simply place an object on a table, the object pushes back. Working out the magnitude of these forces is important in engineering so that structures can be built with members which will withstand the forces involved, i.
Static Friction Friction is a reactive force which opposes motion. Friction can have beneficial or detrimental consequences. When you try to push a piece of furniture along the floor, the force of friction pushes back and makes it difficult to slide the furniture.
This is an example of a type of friction known as dry friction, static friction or stiction. Friction can be beneficial. Without it everything would slide and we wouldn't be able to walk along a pavement without slipping. Tools or utensils with handles would slide out of our hands, nails would pull out of timber and brakes on vehicles would slip and not be of much use.
Viscous Friction or Drag When a parachutist moves through the air or a vehicle moves on land, friction due to air resistance, slows them down.
If you try to move your hand through water, the water exerts a resistance and the quicker you move your hand, the greater the resistance. These reactive forces are known as viscous friction or drag. Electrostatic and Magnetic Forces Electrically charged objects can attract or repel each other. Similarly like poles of a magnet will repel each other while opposite poles will attract.
First Law "An object will continue in its state of rest or motion in a straight line provided no external force acts on it" Basically, this means that if for instance a ball is lying on the ground, it will stay there. If you kick it into the air, it will keep moving.
If there was no gravity, it would go on for ever. However, the external force, in this case, is gravity which causes the ball to follow a curve, reach a max altitude and fall back to the ground.
Another example is if you put your foot down on the gas and your car accelerates and reaches top speed. When you take your foot off the gas, the car slows down, The reason for this is that friction at the wheels and friction from the air surrounding the vehicle known as drag causes it to slow down. If these forces were magically removed, the car would stay moving forever. Second Law "The acceleration of a body is directional proportional to the force which caused it and inversely proportional to the mass and takes place in the direction which the force acts" This means that if you have an object and you push it, the acceleration is greater for a greater force.
So a horse power engine in a sports car is going to create loads of thrust and accelerate the car to top speed rapidly.
The Mighty F = ma
Imagine if that engine was placed into a heavy train locomotive and could drive the wheels. Because the mass is now so large, the force creates much lower acceleration and the locomotive takes much longer to reach top speed.
A force of 10 newtons is applied to a mass of 2 kilos. What is the acceleration? What is the weight of a 10 kg mass? When you push on a spring, the spring exerts a force back on your hand. If you push against a wall, the wall pushes back.
Calculating Force from Velocity and Mass + some common misconceptions - Unity Forum
When you stand on the ground, the ground supports you and pushes back up. If you try to stand on water, the water cannot exert enough force and you sink. Foundations of buildings must be able to support the weight of the construction. Columns, arches, trusses and suspension cables of bridges must exert enough reactive compressive or tensile force to support the weight of the bridge and what it carries.