Answer to Question #85675 in Mechanics | Relativity for SHAABAN

Question

write short notes on the following forms as applied to motion in strait line :
a) Speed
b) Velocity
c)Acceleration
d)Deceleration

Answer 1

a) Speed: The total distance travelled by the particle in unit time is called speed. It is a scalar quantity. It has only magnitude. Thus,

Speed= distance/time

Its dimension is M0L1T-1

Its unit is m/s or km/hour or ft/sec etc.

b) Velocity: The total displacement (Final position- Initial position) done by the particle in unit time is called velocity. It is a vector quantity and has both magnitude and direction. It may have lesser value or same value depending upon the direction traversed by particle. Thus,

Speed= displacement/time

Its dimension is same as of speed M0L1T-1

Its unit is same as of speed m/s or km/hour or ft/sec etc.

c) Acceleration: The rate of change of velocity of particle is the acceleration. It is the first derivative of velocity or the second derivative of position of particle with respect to time. The terms acceleration is generally used to increase of velocity per unit time. Means final velocity of particle is more than initial velocity. It bears both magnitude and direction and hence a vector quantity.

Its dimension is same as of speed M0L2T-1

Its unit is same as of speed m2/s or km2/hour or ft2/sec etc.

d) Deceleration: The rate of change of velocity of particle is the acceleration. It is the first derivative of velocity or the second derivative of position of particle with respect to time. The terms deceleration is generally used to decrease of velocity per unit time. It is possible only if final velocity of particle is less than initial velocity. It bears both magnitude and direction and hence a vector quantity.

Its dimension is same as of speed M0L2T-1

Its unit is same as of speed m2/s or km2/hour or ft2/sec etc.