Forces And Motion Flashcards
(26 cards)
What is a scalar quantity?
A scalar quantity has magnitude only and no specific direction.
What is a vector quantity?
A vector quantity has both magnitude and a specific direction.
What is the difference between scalar and vector quantities?
Scalar quantities have only magnitude, while vector quantities have both magnitude and direction.
Give examples of scalar and vector quantities.
Scalars: distance, speed, mass, energy. Vectors: displacement, velocity, force, acceleration, momentum.
What is velocity?
Velocity is speed in a stated direction.
What is the formula for average speed?
average speed = distance ÷ time
What is the formula for distance?
distance = average speed × time
How do you find speed from a distance-time graph?
By calculating the gradient of the graph.
What is the formula for acceleration?
acceleration = (final velocity - initial velocity) ÷ time
What is the formula for uniform acceleration?
v² - u² = 2 × a × x
What does the gradient of a velocity-time graph represent?
The gradient represents acceleration.
How do you calculate distance from a velocity-time graph?
By finding the area under the graph.
Name a method to measure the speed of an object in a lab.
Use of light gates.
What are typical speeds for walking, running, and cycling?
Walking ~1.5 m/s, Running ~3 m/s, Cycling ~6 m/s.
What is the value of acceleration due to gravity on Earth?
10 m/s².
State Newton’s First Law.
An object stays at rest or moves at constant velocity unless acted on by a resultant force.
What does Newton’s Second Law state?
Force = mass × acceleration (F = m × a).
Define weight and its formula.
Weight is the force due to gravity: weight = mass × gravitational field strength (W = m × g).
How is weight measured?
Weight is measured using a newtonmeter (spring balance).
What is the relationship between weight and gravitational field strength?
Weight is directly proportional to the gravitational field strength.
Why does an object in circular motion have changing velocity?
Because the direction of motion changes, so velocity (a vector) changes.
What provides the force for circular motion?
Centripetal force directed towards the centre of the circle.
What is inertial mass?
It’s a measure of how difficult it is to change an object’s velocity, defined as force ÷ acceleration.
State Newton’s Third Law.
For every action, there is an equal and opposite reaction.
