# P2 Unit 3: Motion and Forces

• Created by: nicola
• Created on: 25-05-15 11:39
What is the different between speed and velocity?
Speed is a scalar it only has size e.g. 125m/s so it does not tell you which direction you are going in. Velocity is how fast you are going in a started direction e.g. 150m/s north. So for example you could have a speed of 3m/s.
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How do distance and time graph work? 1/2
Time is drawn along the x-axis (horizonal axis). The steeper the gradient of a distance/time graph the greater the speed. A horizonal line shows when the object is stationary. Speed can be calculated by dividing the change in distance by the time tak
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How do distance and time graph work? 2/2
Speed can be calculated by dividing the change in distance by the time taken for this change in distance to happen.
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What is acceleration?
Acceleration is how much the velocity is changing every second measured in m/s2.
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What are velocity/time graph? 1/2
Time is drawn along the x-axis (horizontal axis). The steeper the gradient of a velocity/time graph the greater the acceleration.
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What are velocity/time graph? 2/2
A horizontal line shows when the object is travelling at a constant velocity. Acceleration can be calculated by dividing the change in velocity by time taken for the change in velocity to happen.
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How to draw forces diagrams?
Arrows on a force diagram represent the forces on an object. The length of the arrows is proportion to the size of the force and th direction of the arrow shows the direction of the force.
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What are action and reaction forces? 1/2
When two object connect the forces they exrt on each other are always equal and opposite. E.g. Roar and water, bottom and chair, tires and road. Action forces can be consired as the primary force.
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What are action and reaction forces? 2/2
reaction forces can be consided as the resistance forces to an action force. E.g When you apply an action force to a wall by leaning on it the wall pushes back (resists) with a reaction forces. The more you push the more the wall pushes back.
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How do you Calculate the resultant forces?
Forces that are acting in the same direction are added together, forces acting in the same direction are added together, forces acting in oppsite direction are subtracted until only on forces remains this is known as the resulting forces.
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What is the effeect of the resultnat force?
No resultant force wil mean the object remains at a constant velocity (stationary or moving at the same velocity). An object with a resultant force acting on it will accelerate (change velocity).
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How can you find how much an object accelerates?
Mass (kg) the greater the mass the smaller the acceleration (for the same force). Force (N) the greater the resultant force applied to the object the greater the acceleration (for the same mass).
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What meant by weight? 1/2
Weight is the force (N) an object is pulled down with by gravity. it always acts towards the centre of the planet, moon etc. The size of the force depends on the object mass and how strong the gravitation field strenght (g) is.
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What meant by weight? 2/2
On Earth each Kg is pulled down with a force of 10N (the gravitational field strenght is 10N/kg).
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What happens with falling object in space.
In space (a vacum) all objects will accelerate towards the Earth, Planet, moon etc. continually at the same rate because there is nothing in the way to act aginst the force of gravity. (Earth cause objects to accelartate towards it at 10/m/s2.
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## Other cards in this set

### Card 2

#### Front

How do distance and time graph work? 1/2

#### Back

Time is drawn along the x-axis (horizonal axis). The steeper the gradient of a distance/time graph the greater the speed. A horizonal line shows when the object is stationary. Speed can be calculated by dividing the change in distance by the time tak

### Card 3

#### Front

How do distance and time graph work? 2/2

### Card 4

#### Front

What is acceleration?

### Card 5

#### Front

What are velocity/time graph? 1/2