P9 - Motion Flashcards
What is the difference between distance and displacement?
distance - scalar, how far an object moves
displacement - vector, how far an object has moved in a given direction
How is speed different from velocity? Give an example where they are distinguished:
speed - scalar, the rate of change of distance
velocity - vector, speed with a given direction
-uniform circular motion has a constant speed, but changing velocity as it is always changing direction
What are some typical values for walking, running, and cycling speed? What factors can affect this speed?
walking - 1.5ms⁻¹
running - 3ms⁻¹
cycling - 6ms⁻¹
-age, terrain, fitness ability, distance travelled
What is a typical value for the speed of sound in air?
330ms⁻¹
How can speed be found from a distance-time graph?
gradient (may involve drawing a tangent at the given point if accelerating)
What is acceleration, and how can it be calculated and found from a graph?
rate of change of velocity
a = ∆v/t
(gradient from velocity-time graph)
Describe what is happening from point A to B:
uniform/constant acceleration
How can distance be found from a velocity-time graph?
the area under the curve
This graph shows a ball being dropped.
Explain how this graph shows an energy transfer from the ball to the Earth:
-the height at the top of the bounce is less than the height it was dropped from (look at the area of the 2 triangles)
-this means the ball has lost kinetic energy, and has transferred it to the ground
-total energy of the ball and the ground remain constant though
State Newton’s first law of motion:
-if resultant force acting on an object is zero and:
-the object is stationary, it remains stationary
-the object is moving, it continues to move at the same speed and direction (same velocity)
State Newton’s third law of motion:
when two objects interact, the forces they exert on each other are equal but opposite in direction
