Movement and position Flashcards
What does it mean if a distance/time graph is in a straight horizontal line?
The distance is not changing and the speed is 0
What does it mean if the distance time graph is a straight sloping line
The distance from the start point is changing uniformly and the speed is constant.
How do you calculate the average speed on an object?
Average speed = distance moved/time taken
How do you calculate speed?
Speed = distance/time
How can you convert km/h into m/s?
Divide it by 3.6
How do you work out the speed of an object using a distance time graph?
Change in y coordinate/ Change in x coordinate
How can you calculate acceleration?
Acceleration = change in velocity/time
What is the symbol equation for acceleration?
a = deltaV / t
What is a vector quantity?
A quantity in which direction is important too.
What does it mean if a velocity time graph is a straight horizontal line
The speed is constant and the acceleration is zero.
What does it mean if a velocity time graph is a straight sloping line?
The speed is changing uniformly and the acceleration is constant.
How can you determine acceleration from a velocity time graph?
Change in y coordinate / Change in x coordinate
What does it mean if a velocity time graph is curved?
The gradient is increasing then decreasing so the acceleration is increasing then decreasing.
How do you determine the distance travelled from a velocity-time graph?
The area underneath the graph line.
What are the vector quantities? (ones that aren’t here are scalar)
displacement (distance), velocity, momentum, acceleration, force, weight
Why is force an important vector quantity?
Because the direction in which a force acts is clearly important. A resultant force acting in the same direciton as a moving object will increase its speed while a resultant force acting in the opposite direction will decrease its speed - and a force acting at right angles will have no effect on its speed.
If two or more forces act on an object, then their directions must be taken into account when calculating the resultant force acting.
What happens when forces of 3N and 4N are acting on an object in the same direction?
the forces just add together to give a resultant force of 7N
What happens when forces of 3N and 4N act on an object in opposite directions?
the forces subtract to give a resultant force of 1N in the direction of the 4N force
Why does the velocity of something decrease to zero (changes) when it hits something?
Because an unbalanced force acts on it
