Motion Flashcards
What is rest?
If the position of an object does not change as time passes, then it is said to be at rest.
What is motion?
If the position of an object changes as time passes, then it is said to be in motion.
Can an object be at rest and in motion at the same time?
Yes, an object can be at rest with respect to one thing and in motion with respect to another at the same time.
What is the origin in motion?
To locate the position of an object, we have to choose a suitable reference point called the origin.
What is distance?
The distance travelled by an object is the length of the actual path traversed by the object during motion. It is a scalar quantity.
What is displacement?
The displacement of an object in motion is the shortest distance between the initial position and the final position of the object. It is a vector quantity.
Can distance travelled be zero or negative?
The distance travelled by an object in motion can never be zero or negative.
Can displacement be positive, zero, or negative?
The displacement of an object can be positive, zero, or negative.
Do distance and displacement have the same units?
Yes, both distance and displacement have the same units.
What is uniform motion?
An object is said to be in uniform motion if it travels equal distances in equal intervals of time, however small the intervals may be.
What is non-uniform motion?
An object is said to have non-uniform motion if it travels unequal distances in equal intervals of time.
What is speed?
Speed of a body is defined as the distance travelled by the body in unit time. The SI unit of speed is metre/second (m/s).
How is speed calculated?
If ‘s’ is the distance travelled by a body in time ‘t’, then its speed ‘v’ is given as v = s/t.
Is speed a scalar or vector quantity?
Speed of a body is a scalar quantity. It can be zero or positive but can never be negative.
What is uniform speed?
If a body covers equal distances in equal time intervals, however small the intervals may be, then it is said to have uniform speed.
What is non-uniform speed?
If a body covers unequal distances in equal time intervals, however small the intervals may be, then it is said to have non-uniform speed.
What is average speed?
For bodies moving with non-uniform speed, we describe the rate of motion in terms of their average speed.
What is velocity?
Velocity of a body is defined as the distance travelled by the body in unit time in a given direction.
Is velocity a scalar or vector quantity?
Velocity of a body is a vector quantity. It can be positive, negative, or zero.
What is uniform velocity?
A body is said to be moving with uniform velocity if it travels along a straight line, covering equal distances in equal intervals of time.
What is non-uniform velocity?
A body is said to be moving with non-uniform velocity if it covers unequal distances in a particular direction in equal intervals of time.
What is acceleration?
Acceleration of a body is defined as the rate of change of its velocity with time.
Is acceleration a scalar or vector quantity?
Acceleration is a vector quantity. It can be positive, negative, or zero.
What happens to acceleration when velocity increases?
If the velocity of a body increases, then the acceleration is positive.
What happens to acceleration when velocity decreases?
If the velocity of a body decreases, then the acceleration is negative. Negative acceleration is called retardation.
What is a distance-time graph?
The distance-time graph of a body moving with uniform speed is a straight line.
What does the slope of a distance-time graph represent?
Speed of a body can be obtained from the slope of the distance-time graph.
What is a velocity-time graph?
The velocity-time graph of a body moving with uniform velocity is a straight line parallel to the time axis.
What does the area under a velocity-time graph represent?
The magnitude of displacement or distance travelled by the body is equal to the area enclosed by the velocity-time graph and time axis.
What are the equations of motion?
The three equations of motion of a body moving along a straight line with uniform acceleration are: v = u + at, s = ut + (1/2) at², v² - u² = 2as.
What is uniform circular motion?
When a body moves along a circular path with a uniform speed, its motion is called uniform circular motion.
What is centripetal force?
The external force needed to make a body travel in a circular path is known as centripetal force.