Transcript Speed and Acceleration

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
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
Speed-time graph
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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