Forces and Motion Flashcards
What is a vector quantity?
A quantity with both size and direction.
What is a scalar quantity?
A quantity of size but has no direction.
Name a vector quantity.
Force, velocity, momentum etc.
Name a scalar quantity.
Distance, speed, energy, time etc.
What is the equation used to calculate speed?
Speed = Distance / Time
Rearrange the equation used to calculate speed, to find out distance instead?
Distance = Speed x Time
Rearrange the equation used to calculate speed, to find out time instead?
Time = Distance / Speed
What does a horizontal line on a distance/time graph mean?
The object is stationary.
What does a straight, sloping line on a distance/time graph mean?
The object is moving at a constant speed.
What does the gradient of the line on a distance/time graph tell us?
The speed the object is travelling.
What is the equation used to calculate acceleration?
Acceleration = change in velocity (final - initial) / time taken
A man walks 100 metres in 25 seconds. What is his speed?
Speed = distance / time
100m / 25s = 4 m/s
A car accelerates from 2 m/s to 10 m/s in 4 seconds. What is the car’s acceleration.
Acceleration = change in velocity (final - initial) / time
10 m/s - 2 m/s = 8 m/s
8 m/s / 4s = 2 m/s^2
Which equation links acceleration, initial velocity, final velocity and distance travelled?
(Final velocity)^2 - (initial velocity)^2 = 2 x acceleration x distance
What value is known as the acceleration due to gravity?
10 m/s^2
What does the horizontal line show on a velocity/time graph?
The object is moving at a constant velocity.
What does a sloping line on a velocity/time graph mean?
The object is accelerating.
What does a line below the horizontal axis on a velocity/time graph show?
The object is moving in the opposite direction.
What does the area under a velocity/time graph represent?
The distance the object has travelled.
What is Newton’s first law of motion?
A moving object will continue to move at the same speed in the same direction unless an external force acts on it and a stationary object will remain at rest unless an external force acts on it.
What is mass?
The amount of matter there is in an object.
What is weight?
A measure of the pull of gravity on an object (depends on the strength of gravity).
What is the equation used to calculate weight?
Weight = mass x gravitational field strength
What is Newton’s second law of motion?
Acceleration in the direction of a resultant force depends on the size of the force and the mass of the object.
