Velocity-time $(v-t)$ graph for a moving object is shown in the figure. Total displacement of the object during the time interval when there is non-zero acceleration and retardation is........$m$

The velocity of a body depends on time according to the equation $v = 20 + 0.1{t^2}$. The body is undergoing

A small block slides without friction down an inclined plane starting from rest. Let ${S_n}$be the distance travelled from time $t = n - 1$ to $t = n.$ Then $\frac{{{S_n}}}{{{S_{n + 1}}}}$ is

The displacement of a particle, moving in a straight line, is given by $s = 2{t^2} + 2t + 4$ where $s$ is in metres and $t$ in seconds. The acceleration of the particle is........$ms^{-2}$

Read each statement below carefully and state with reasons and examples, if it is true or false 

A particle in one-dimensional motion

$(a)$ with zero speed at an instant may have non-zero acceleration at that instant

$(b)$ with zero speed may have non-zero velocity.

$(c)$ with constant speed must have zero acceleration.

$(d)$ with positive value of acceleration must be speeding up.