Calculating Speed 1 Speed can be calculated by

Calculating Speed 1. Speed can be calculated by Speed = Distance/Time 2. A distance-time graph can be used to see when an object is stationary or travelling at a constant speed. 3. The steeper the slope, the faster the speed. The gradient of a distance-time graph shows the speed.

Distance-time graph

Speed equation

Velocity-time graphs 1. Velocity includes the speed of an object and the direction in which it travels. 2. Velocity-time graphs can be used to see when an object is moving with constant velocity or constant acceleration. 3. The steeper the slope, the greater the acceleration. 4. The gradient of a velocity-time graph shows the acceleration. 5. The area underneath a velocity-time graph shows distance travelled.

Speed-time graph

Acceleration 1. Acceleration is the rate at which velocity changes. 2. Acceleration = Change in velocity / Time taken 3. Acceleration depends on the mass of the object and the force applied 4. Acceleration = Force/Mass 5. Acceleration can be increased by reducing mass and increasing the force of the engine

Acceleration

Stopping distances 1. The greater the speed of a vehicle, the greater the braking force needed to stop it. 2. Skidding occurs if the braking force is too great (there is not enough friction between the tyres and the road). 3. Stopping distances depend on the speed of the car, driver reaction times, the type of surface, tyre quality, brake quality, and weather conditions

Braking distance

Car crash

Quiz

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