Motion Flashcards
What is weight?
Weight is a force that acts towards the centre of the earth, it’s a vectors
What are vectors?
Quantities that have both a size and a direction
What is mass?
Mass measures the amount of matter in something and does not have a direction
What are examples of scalar quantities?
Distance, speed, energy, mass
What is displacement?
Displacement is the distance covered in a straight line and has a direction. The displacement at the end of a journey is usually less than the distance travelled because of the turns or bends in a journey
Name some vectors
Force, weight, displacement, acceleration, momentum
What does the speed of an object tell you?
It tells you how far it moves in a certain time, velocity
What is acceleration
A measure of how fast velocity is changing
What is momentum?
A combination of mass and velocity
What are some common units for speed?
Metres per second (m/s)
Kilometres per hour (Km/h)
Miles per hour (mph)
What is average speed worked out from?
From the total distance travelled and the total time taken
What is the instantaneous speed?
The speed at a particular point in a journey
How can speed be calculated?
Speed = distance ➗ time taken
To measure speed in the laboratory you need to measure a distance and a time, for fast moving objects what would you use?
Light gates to measure time because they will be more accurate then using a stop watch
What do the characteristics mean on a distance/time graphs?
Horizontal lines mean the object is stationary (it’s distance from the starting point is not changing)
Straight, sloping lines mean the object is travelling at a constant speed
The steeper the line, the after the object is travelling
The speed is calculated from the gradient of the line
If a moving object changes its velocity or direction, what happening?
It’s accelerating
What does acceleration tell you?
It tells you the change in velocity each second, so the units of acceleration are metres per second written as m/s to the power of 2
How do you work out acceleration?
Acceleration = change in velocity ➗ time taken
What does v mean?
Velocity
What does a mean?
Acceleration
What does u mean?
Initial velocity
What does t mean?
The time take for the change in velocity
Acceleration does not always mean getting faster. An acceleration can also cause an object to get slower. What is this called?
Deceleration, the acceleration will have a negative value
Acceleration can be related to initial velocity, final velocity and distance travelled by using what equation?
V squared - u squared = 2 ✖️ a ✖️ X