What is Motion?
When a body is continuously changing its position with respect to the
surroundings, then we say that the body is in motion.
What is speed?
The quantity by which we can measure how fast a body moves or distance traveled,
is called speed.
What is a scalar quantity?
Physical quantities which can be fully expressed by a magnitude only are
called scalar quantities. Length, mass, speed, work, energy, time,
temperature, etc. are examples of scalar quantities.
What is a vector quantity?
Physical quantities which need both magnitude and direction to be fully
expressed are called vector quantities. Displacement, velocity, acceleration,
force, electric intensity, etc. are examples of a vector quantity.
What is negative acceleration or retardation?
The rate of decrease of velocity of a body with time is called negative
acceleration or retardation.
