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Description
Flashcards by Carmen Diaz, updated more than 1 year ago
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Created by Carmen Diaz
over 5 years ago
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| Question | Answer |
| What's a force? | A force is a push or a pull on an object that is caused by it interacting with something |
| What's a vector quantity? | Vector quantities have a magnitude and a direction |
| Examples of vector quantities? | -Force -Velocity -Displacement -Acceleration -Momentum |
| What's a scalar quantity? | Scalar quantities only have a magnitude and don't have a direction |
| Examples of scalar quantities? | -Speed -Distance -Mass -Temperature -Time -Energy |
| What are the two types of forces? | -Contact forces -Non-contact forces |
| What's a contact force? | A contact force is when two objects have to be touching for the force to act |
| Examples of contact forces? | -Friction -Air resistance -Tension in rope -Normal contact force |
| What's a non-contact force? | A non-contact force is when two objects don't need to be touching for the force to act |
| Examples of non-contact forces? | -Magnetic force -Gravitational force -Electrostatic force -Nuclear force |
| What's an interaction pair? | An interaction pair is a pair of forces that are equal and opposite and act on two interacting objects. (NEWTON'S THIRD LAW) |
| What's gravitational force? | Gravitational force is the force of attraction between masses |
| Two important effects of gravitational force | -On the surface of a planet, it makes all things fall towards the ground -It gives everything weight |
| What's the gravitational field strength in Earth? | The gravitational field strength in Earth is 9.81 |
| How does the gravitational field strength vary with location? | The gravitational field strength it's stronger the closer you are to the mass causing the field (for example Earth), and stronger for larger masses |
| What's mass? | Mass is just the amount of 'stuff' in an object. For any object it's mass will be the same value |
| Is mass a force? | Mass is not a force |
| What's mass measured? | Mass is measured in kilograms (kg) with a mass balance |
| What's weight? | Weight is the force acting on an object due to gravity (the pull of the gravitational force on the object) |
| What does weight depend on? | Weight depends on the strength of the gravitational field at the location of an object. This means that the weight of an object changes with its location |
| What's weight measured? | Weight is measured in newtons (N) using a calibrated spring balance |
| Formula for weight | WEIGHT (N) = MASS (kg) * GRAVITATIONAL FIELD STRENGTH (N/kg) |
| Differences between weight & mass | -Weight is a force, mass isn't -Mass always stays the same, weight changes depending of the location of the object |
| Is mass & weight directly proportional to each other? | Yes, mass & weight are directly proportional. As increasing the mass of an object increases it's weight. Weight & mass are directly proportional because if you double the mass the weight doubles too. |
| What's a resultant force? | Resultant force is a single force that has the same effect as all the original forces together |
| What does the resultant force do? | The resultant force moves an object through a distance, so energy is transferred and work is done on the object |
| Formula for resultant force | RESULTANT FORCE (N) = MASS (kg) * ACCELERATION (m/s2) |
| When is work done? | Work is done only when a force is applied on an objects and causes the object to move in the same direction as the force |
| Consequences moving a object? | The thing applying the force needs a source of energy (like fuel ir food), so the resultant force does 'work' and moves the object and energy is transferred from one store to another. (Work done and energy transferred are the same thing) |
| Formula for work done | WORK DONE (J) = FORCE (N) * DISTANCE (m) |
| What's the centripetal force? | The centripetal force is the force towards the center of the circle |
| What does centripetal force create? | -Changing direction -Acceleration -Velocity |
| Important equation of motion | FINAL VELOCITY (m/s) = INITIAL VELOCITY (m/s) + TIME (s) + 1/2 * ACCELERATION (ms-2) * (TIME (s))2 |
| Distance-time graphs shape | - Gradient = speed (The steeper the graph, the faster the object is going) -Flat sections are where the object's stationary, it's stopped -Straight uphill sections mean it is traveling at a steady speed -Curves represent acceleration or deceleration -A steepening curve means the object's speeding up (increasing gradient) -A leveling off curve means it's slowing down (decreasing gradient) |
| Formula for gradient in distance-time graphs | GRADIENT = CHANGE IN DISTANCE (m) / CHANGE IN TIME (s) = VELOCITY |
| Velocity-time graphs shape | -Gradient = acceleration, as acceleration is change in velocity / time -Flat sections represent traveling at a steady speed - The steeper the graph, the greater the acceleration or deceleration -Uphill sections are acceleration. Downhill sections are deceleration. A curve means changing acceleration |
| Formula for gradient in velocity-time graphs | GRADIENT = CHANGE IN VELOCITY (m/s) / CHANGE IN TIME (s) = ACCELERATION (m/s/s) |
| What's hooks law? | ...? |
| What's Newton's first law? | Newton's first law is that an object in equilibrium will continue in it's current state of motion unless acted upon by an external force |
| What's Newton's second law? | Newton's second law is that the acceleration of an object i proportional to the resultant force that is producing it. Force is directly proportional to acceleration |
| Formula for Newton's second law | FORCE (N) = MASS (kg) * ACCELERATION (m/s/s) |
| What's Newton's third law? | Newton's third law is when two objects interact, the forces they exert on each other are equal and opposite |
| What's inertia? | Inertia is the tendency for motion to remain unchanged (to continue in the same state of motion) |
| How do you make an object stretch, compress or bend? | To stretch, compress or bend an object yo need more than one force acting on the object. Otherwise the object would simply move in the direction of the applied force, instead of changing shape |
| What is work done transferred to? | Work done when an object stretches or compresses, the energy is transferred to elastic potential energy store of the object |
| What's elastic deformation? | Elastically deformed is when an object can go back to its original shape and length after the force has been removed |
| What are elastic objects? | Elastic objects are objects that can be elastically deformed |
| What's inelastic deformation? | Inelastically deformed is when an object doesn't return to its original shape and length after the force has been removed |
| Formula for extension of a spring | FORCE (N) = SPRING CONSTANT (N/m) * EXTENSION (m) |
| Is the extension of the spring directly proportional to the force? | Yes, the extension of the spring is directly proportional to the force |
| What's the limit of proportionally? | The limit of proportionally is the limit to the amount of force you can apply to an object for the extension to keep on increasing proportionally. There is a maximum force above which the graph curves, showing that the extension is no longer proportional to force |
| What's a moment? | A momento is the turning effect of a force |
| How do you make an object to rotate? | An object to rotate is caused by a force or several forces |
| Formula for moment | MOMENT (Nm) = FORCE (N) * DISTANCE (m) |
| What's pressure? | Pressure is the force per unit area |
| What are fluids? | Fluids are substances that can 'flow' because their particles are able to move around |
| What does a pressure of a fluid mean? | The pressure of a fluid means a force is exerted normal (at right angles) to any surface in contact with the fluid |
| Formula for pressure | PRESSURE (Pa) = FORCE (N) / AREA OF THAT SURFACE (m2) |
| What does pressure in a liquid depend on? | It depends on depth and density |
| What's density? | Density is a measure of the 'compactness' of a substance (how close together the particles in a substance are) |
| How does the density in a liquid or gas vary? | -In a liquid the density is uniform (the same everywhere) and it doesn't vary with shape or size -The density of a gas can vary |
| Formula for pressure at a certain depth | PRESSURE (Pa) = HEIGHT OF THE COLUMN OF LIQUID [THE DEPTH] (M) * DENSITY OF THE LIQUID (kg/m3) * GRAVITATIONAL FIELD STRENGTH (N/kg) |
| What's upthrust? | Upthrust is a force that determines whether an object will sink or float |
| When does an object float? | An object floats if the upthrust in an object is equal to the object's weight, so the forces are balance and the object floats |
| When does an object sink? | An object sinks if the object's weight is more than the upthrust, so the object sinks |
| What's distance? | Distance is how dar an object has moved (it's a scalar quantity, as it doesn't have a direction) |
| What's displacement? | Displacement measures the distance and direction in a straight line from an object's starting point to its finishing point (it's a vector quantity) |
| What's speed? | Speed is just how far you're going with no regard to the direction (it's a scalar quantity) |
| What's velocity? | Velocity is speed in a given direction (it's a vector quantity) |
| Formula for distance travelled | DISTANCE TRAVELLED (m) = SPEED (m/s) * TIME (s) |
| Typical speeds | -A person walking: 1.5 m/s -A person running: 3 m/s -A person cycling: 6 m/s -A car: 25 m/s -A train: 55 m/s A plane: 250 m/s |
| What can wind speed be affected by? | Wind speed can be affected by: -Temperature -Atmospheric pressure -Large buildings or structures nearby |
| What's acceleration? | Acceleration is the rate of change of velocity (how quickly you're speeding up) |
| What's deceleration? | Deceleration is just negative acceleration (when something slows down, the change of velocity is negative) |
| Formula for acceleration | ACCELERATION (m/s/s) = CHANGE IN VELOCITY (m/s) / TIME (s) |
| What's uniform acceleration? | Uniform acceleration means a constant acceleration |
| Formula for uniform acceleration | (FINAL VELOCITY)2 (m/s) - (INITIAL VELOCITY)2 (m/s) = 2 * ACCELERATION (m/s/s) * DISTANCE (m) |
| What's drag? | Drag is the resistance you get in a fluid (a gas or a liquid) |
| What's air resistance? | Air resistance is a type of drag. It's the frictional force produced by the air acting on a moving object |
| Important factor for reducing drag? | The mast important factor in reducing drag is keeping the shape of the object streamlined. This is where the object is designed to allow fluid to flow easily across it, reducing drag |
| Steps of objects falling through fluids | -When falling objects first set off, the force of gravity is much more than the frictional force slowing them down, so they accelerate -As the speed increases the friction builds up -This gradually reduces the acceleration until eventually the frictional force is equal to the acceleration force (so the resultant force is zero) -It will have reached its maximum speed or terminal velocity and will fall at a steady speed |
| What does terminal velocity depend on? | Terminal velocity depends on: -Shape -Area |
| What's gravity? | Gravity is the accelerating force acting on all falling objects and it will make them all fall at the same rate, if it wasn't for air resistance |
| What is terminal velocity of any object determined with? | The terminal velocity of any object is determined by its drag in comparison to its weight |
| What does frictional force depend on? | Frictional force depends on: -Shape -Area |
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