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Description
Flashcards by jaspreetnatt1, updated more than 1 year ago
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Created by jaspreetnatt1
over 9 years ago
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| Question | Answer |
| What units is speed measured in? | M/S, Km/H, MPH |
| What two things do you need to work out the speed? | Distance, Time Taken |
| How does a speed camera work? | It takes two pictures, a certain time apart. The road markings give it the distance. Then it uses the calculation, distance travelled / time taken to determine the speed. |
| What is constant in a distance time graph? | Any line going at an angle. Horizontal lines represent stationary. |
| How do you calculate the speed travelled in a distance-time graph? | Look at the point, then use the speed equation (distance travelled / time) to calculate the speed. |
| What unit is acceleration measured in? | Only M/S² |
| In a speed-time graph: What does a horizontal line represent? | Constant Speed |
| In a speed-time graph: Straight Line Positive Gradient | Constant positive acceleration |
| In a speed-time graph: Striaght Line Negative Gradient | Constant negative acceleration |
| In a speed time graph, how do you calculate the total distance travelled? | Using the area under the lines. |
| What is velocity? | Speed in a given direction |
| What does a negative sign represent in velocity? | Travelling the opposite direction |
| What is acceleration and what does this mean in terms of acceleration? | Acceleration is change in velocity. This means an object accelerates if its speed changes, or direction changes. |
| What does weight do in terms of forces? | It causes the object to speed up |
| What does friction do? | Cause an object to slow down |
| What does air resistance do? | Cause sky divers to slow down. |
| What does acceleration depend on if an unbalanced force acts? | Force applied on object Mass of object |
| What is the equation for resultant force? | Resultant Force (N) = Mass (KG) x Acceleration (M/S²) |
| Define a newton (N) | Force needed to give a mass of 1kg an acceleration of 1 M/S² |
| What happens if the resultant force is 0? | The object remains the same speed |
| What happens if the resultant force is not 0? | The object will speed up or slow down, depending on the direction of the resultant force. |
| What is the Stopping Distance? | The stopping distance is the distance, the car took to stop. This includes the thinking distance, and braking distance. |
| What is thinking distance? | THis is the distance travelled at the time the individual realises the break is required, to the point where it is applied. |
| What is Braking Distance? | This is the distance it takes the vehicle to stop once the brake has been applied. |
| What factors increase the Braking Distance? | - Being Tired - Distracted - Driver's Ill -Under the influence of alcohol / drugs |
| What factors increase the braking distance? | - Vehicle is travelling fast - Poor weather conditions / bad road conditions - Vehicle is in bad condition, e.g. tyres worn out, brake is damaged. |
| What are the scientific factors behind the stopping distance increases? Including mass, friction and tyres? | Mass Increase = Greater KE Bad Road Conditions = Less Friction Worn Out Tyres = Less Braking Force |
| What is the relationship in thinking distance? | It's a linear relationship. Double speed = double distance travelled. (Only at constant speed) |
| What is the relationship in Braking Distance? | It's a squared relationship. Double speed = quadruple braking distance. Triple Speed = Multiply braking distance by 9 |
| How to mass and weight differ? | Mass is the measure of how much stuff there is in an object. Weight includes the forces acting on the object. |
| What are the Gravitialional Field Strengths of Earth and the Moon? | Earth = 10 N/kg Moon = 1.6 N/kg |
| What is work and give an example. | Work is when a force moves something, an example of this is opening a door. |
| What is required to do work and what are they both measured in (unit)? | Work requires energy. Energy and Work are both measured in Joules (J) |
| What does the amount of work done depend on? | Size of Force (N) Distance object moves (M) |
| What is power and what unit is it measured in? | Power is how quickly work is done, and is measured in Watts (W) |
| Why is having a higher power rating bad? | It causes high fuel consumption, this is both expensive for the driver and bad for the environment. |
| What does the KE of an object depend on? | - Mass (KG) - Speed (M/S) |
| What happens to the braking distance of a car, if it has a lot of KE? | The braking distance of the car increases. |
| What is the problem of cars relying on petrol and diesel to power their cars? | The creation of these fuels requires fossil fuel, fossil fuel is finite and is running out. |
| What are Bio - Fuels? | These are produced by living things or their products. E.g. bioethanol = plant sugars Biodiesel = plant oils |
| List the advantages of Bio-Fuel | - Renewable - May lead to an overall reduction in emissions of CO2 |
| What is the use of Solar Power in cars? | Solar and Light energy is both electrical energy. The electrical energy can be used to power the motor in the car. |
| What's a disadvantage of solar power? | The creation of solar panels can cause pollution during production. |
| What does car fuel consumption depend on? | - Energy required to increase the KE - Energy required to work against friction - Driving style, speed and road condition |
| What is the relationship between the shape of the vehicle and the fuel consumption? | If the vehicle is streamline, this decreases the air resistance that acts on the vehicle when the car moves. This decreases the cars fuel consumption and increases the range. |
| List 3 frictional forces | Drag, Friction, Air Resistance |
| Frictional forces can act against the movement of the object slowing it down. How can these forces be reduced? | Changing the shape of the object, Use a lubricant - object slides through the air with less resistance. |
| What are the implications of a greater drag force? | Greater energy loss, which leads to greater fuel consumption. |
| What safety features have been implemented in a car? | Seatbelts Airbags Crumple Zone |
| How do seatbelts, airbags and crumple zones help you in a collision? | -Seatbelts - prevent you propelling forwards but increases stretches in a collision, increasing the body's momentum time to reach 0. Reduces the force. - Air Bag - Increases the head's momentum time to reach 0, reduces force and cushions and prevents cuts. -Crumple Zone - Crumples in a controlled way during a collision. Increases the time taken for momentum to reach 0, therefore reducing the force. |
| What does a collapsible steering column do? | Absorbs energy and breaks to avoid driver being impaled. |
| What's the safety cage in a car? | It's a rigid section in a car, that does not absorb energy. It strengthens the cabin section in the vehicle preventing the vehicle from collapsing when the car tips over. |
| What does Anti-Lock Braking System (ABS) do? | Prevents tyres form skidding, allowing the driver to stay in control. They work by turning the brakes on and off automatically. This increases the area of the type that is in contact with the road increasing friction. This reduces the braking distance and the vehicle is able to stop quicker. |
| What does traction control do? | Prevents the car from skidding when the car accelerates. Helps the driver escape dangerous situations quickly. |
| What happens with more momentum? | Difficulty changing directions quickly. |
| What happens to the momentum during a crash? | The momentum decreases, as it decreases the passengers feel a force which can result in injury for example, whiplash. |
| How is the force affected, if the rate of chnage of momentum is fast? | The quicker the decrease in momentum, the greater the force. |
| How can you reduce the stopping forces? | - Increase stopping / collision time, - Increase the stopping / collision distance. |
| Using a law of motion, how can force be decreased? | Newton's Second Law of Motion states, if the collision stopping time is increased, using a crumple zone for example, the rate of acceleration is decreased so the force is decreased. |
| What is terminal speed? | This is where the drag force is equal to the weight. This is also when the object is at its top speed. |
| How does the area of the object affect the drag? | More area of object = more drag = slower Less area of object = less drag = faster. |
| What happens to the kinetic energy if an object is falling at terminal speed? | The KE is not increasing, therefore the speed is not changing. |
| What happens to the GPE during terminal speed? | The GPE decreases as the object does work against the friction. The GPE is transferred into internal or thermal energy of the surrounding air particles by friction. Remember: ONCE AT TERMINAL SPEED, KE CANNOT BE INCREASED, THUS THE GPE CANNOT BE CONVERTED INTO KE. |
| What are the factors of GPE or acceleration due to gravity? | -It is unaffected by the atmospheric change, -Varies slightly at different points on Earth -Is different on top of a mountain or down a mineshaft. |
| What factors does GPE of an object depend on? | - Mass - Height |
| What's Earth's Gravitational Field Strength? | 10N/kg |
| What happens to GPE when an object falls? | It's converted into KE. |
| What happens if the mass is doubled to the KE? | The KE is doubled. |
| What happens to the KE if the speed is doubled? | The KE quadruples. |
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