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Flashcards in P4.1 Deck (12):

1. What is the equation for average speed?

-speed (m/s) = distance travelled (m) / tIme taken (s)


2. What is the difference between average speed and instantaneous speed for examples of motion where speed is changing?

-average speed: how much distance an object covers over a certain time span (doesn’t tell you exact motion at certain points)
-instantaneous speed: an average over a short time interval, tells you the exact speed the object is moving at, at an instant in time


3. What is the displacement of an object at a given moment?

-its distance from its starting point with an indication of direction
-displacement can be positive or negative depending on its direction


5. What does the gradient of a distance-time and displacement-time graph tell us?

-Distance-time graph: gradient= speed
-Displacement-time graph=velocity


5. What happens as the gradient gets steeper in a distance/displacement-time graph?

-the steeper the gradient, the faster the object is going (higher speed)


6. How do you calculate a speed from the gradient of a straight section of a distance-time graph?

Speed= gradient= vertical/horizontal= distance/time


8. What does acceleration mean in many everyday situations?

-the change in speed of an object in a given time interval


8. What is deceleration?

-negative acceleration (if something slows down the change in velocity will be negative)


9. What is the instantaneous velocity of an object?

-its instantaneous speed with an indication of the direction


10. What happens to velocity if an object moves in the opposite direction?

-the velocity of an object moving in a straight line is positive if it is moving in one direction and negative if it is moving in the opposite direction
-a line can have the same speed but a different velocity


12. How do you calculate the acceleration from the gradient of a velocity–time graph (or from a speed-time graph in situations where direction of motion is constant)?

Acceleration= gradient=horizontal/vertical


13. What is the equation for acceleration?

Acceleration (m/s2) = change in velocity (m/s) / time taken (s)