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
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)?